72657678647866 has 24 divisors (see below), whose sum is σ = 121556901175164. Its totient is φ = 32377957584000.

The previous prime is 72657678647833. The next prime is 72657678647899. The reversal of 72657678647866 is 66874687675627.

It is an interprime number because it is at equal distance from previous prime (72657678647833) and next prime (72657678647899).

It can be written as a sum of positive squares in 6 ways, for example, as 51117080443641 + 21540598204225 = 7149621^2 + 4641185^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1661408635 + ... + 1661452366.

Almost surely, 2^{72657678647866} is an apocalyptic number.

72657678647866 is a deficient number, since it is larger than the sum of its proper divisors (48899222527298).

72657678647866 is a wasteful number, since it uses less digits than its factorization.

72657678647866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3322861074 (or 3322861045 counting only the distinct ones).

The product of its digits is 47795650560, while the sum is 85.

The spelling of 72657678647866 in words is "seventy-two trillion, six hundred fifty-seven billion, six hundred seventy-eight million, six hundred forty-seven thousand, eight hundred sixty-six".