721900101 has 8 divisors (see below), whose sum is σ = 1036574560. Its totient is φ = 444246192.

The previous prime is 721900099. The next prime is 721900141. The reversal of 721900101 is 101009127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721900101 - 2¹ = 721900099 is a prime.

It is a super-2 number, since 2×721900101² = 1042279511647620402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721900141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9255091 + ... + 9255168.

It is an arithmetic number, because the mean of its divisors is an integer number (129571820).

Almost surely, 2^721900101 is an apocalyptic number.

It is an amenable number.

721900101 is a deficient number, since it is larger than the sum of its proper divisors (314674459).

721900101 is a wasteful number, since it uses less digits than its factorization.

721900101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18510275.

The product of its (nonzero) digits is 126, while the sum is 21.

The square root of 721900101 is about 26868.1986928785. The cubic root of 721900101 is about 897.0686939458.

Adding to 721900101 its reverse (101009127), we get a palindrome (822909228).

The spelling of 721900101 in words is "seven hundred twenty-one million, nine hundred thousand, one hundred one".