721854067369 has 4 divisors (see below), whose sum is σ = 724729980240. Its totient is φ = 718978154500.

The previous prime is 721854067357. The next prime is 721854067381. The reversal of 721854067369 is 963760458127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 963760458127 = 163993 ⋅5876839.

It is an interprime number because it is at equal distance from previous prime (721854067357) and next prime (721854067381).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721854067369 is a prime.

It is a super-2 number, since 2×721854067369² (a number of 25 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721854067309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1437956059 + ... + 1437956560.

It is an arithmetic number, because the mean of its divisors is an integer number (181182495060).

It is a 1-persistent number, because it is pandigital, but 2⋅721854067369 = 1443708134738 is not.

Almost surely, 2^721854067369 is an apocalyptic number.

It is an amenable number.

721854067369 is a deficient number, since it is larger than the sum of its proper divisors (2875912871).

721854067369 is a wasteful number, since it uses less digits than its factorization.

721854067369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2875912870.

The product of its (nonzero) digits is 15240960, while the sum is 58.

The spelling of 721854067369 in words is "seven hundred twenty-one billion, eight hundred fifty-four million, sixty-seven thousand, three hundred sixty-nine".