721665056670038 has 16 divisors (see below), whose sum is σ = 1203372005168256. Its totient is φ = 322331787097920.

The previous prime is 721665056670029. The next prime is 721665056670121. The reversal of 721665056670038 is 830076650566127.

It is a Harshad number since it is a multiple of its sum of digits (62).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 447683036831 + ... + 447683038442.

It is an arithmetic number, because the mean of its divisors is an integer number (75210750323016).

Almost surely, 2^{721665056670038} is an apocalyptic number.

721665056670038 is a deficient number, since it is larger than the sum of its proper divisors (481706948498218).

721665056670038 is a wasteful number, since it uses less digits than its factorization.

721665056670038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895366075319.

The product of its (nonzero) digits is 76204800, while the sum is 62.

The spelling of 721665056670038 in words is "seven hundred twenty-one trillion, six hundred sixty-five billion, fifty-six million, six hundred seventy thousand, thirty-eight".