721665056670040 has 64 divisors (see below), whose sum is σ = 1876560821582400. Its totient is φ = 244647929315328.

The previous prime is 721665056670029. The next prime is 721665056670121. The reversal of 721665056670040 is 40076650566127.

It is a happy number.

It is a congruent number.

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, 14479611049 + ... + 14479660888.

It is an arithmetic number, because the mean of its divisors is an integer number (29321262837225).

Almost surely, 2^{721665056670040} is an apocalyptic number.

721665056670040 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

721665056670040 is an abundant number, since it is smaller than the sum of its proper divisors (1154895764912360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721665056670040 is a wasteful number, since it uses less digits than its factorization.

721665056670040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28959272044 (or 28959272040 counting only the distinct ones).

The product of its (nonzero) digits is 12700800, while the sum is 55.

The spelling of 721665056670040 in words is "seven hundred twenty-one trillion, six hundred sixty-five billion, fifty-six million, six hundred seventy thousand, forty".