721887385 has 8 divisors (see below), whose sum is σ = 877230720. Its totient is φ = 570199344.

The previous prime is 721887379. The next prime is 721887389. The reversal of 721887385 is 583788127.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 721887385 - 2⁹ = 721886873 is a prime.

It is a super-2 number, since 2×721887385² = 1042242793244276450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (721887389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 913387 + ... + 914176.

It is an arithmetic number, because the mean of its divisors is an integer number (109653840).

Almost surely, 2^721887385 is an apocalyptic number.

It is an amenable number.

721887385 is a deficient number, since it is larger than the sum of its proper divisors (155343335).

721887385 is a wasteful number, since it uses less digits than its factorization.

721887385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1827647.

The product of its digits is 752640, while the sum is 49.

The square root of 721887385 is about 26867.9620552062. The cubic root of 721887385 is about 897.0634267385.

The spelling of 721887385 in words is "seven hundred twenty-one million, eight hundred eighty-seven thousand, three hundred eighty-five".