721555057065 has 16 divisors (see below), whose sum is σ = 1154538176256. Its totient is φ = 384812668800.

The previous prime is 721555057039. The next prime is 721555057087. The reversal of 721555057065 is 560750555127.

It is not a de Polignac number, because 721555057065 - 2¹² = 721555052969 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 682116 + ... + 1381445.

It is an arithmetic number, because the mean of its divisors is an integer number (72158636016).

Almost surely, 2^721555057065 is an apocalyptic number.

It is an amenable number.

721555057065 is a deficient number, since it is larger than the sum of its proper divisors (432983119191).

721555057065 is a wasteful number, since it uses less digits than its factorization.

721555057065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2086880.

The product of its (nonzero) digits is 1837500, while the sum is 48.

The spelling of 721555057065 in words is "seven hundred twenty-one billion, five hundred fifty-five million, fifty-seven thousand, sixty-five".