78721402387 has 32 divisors (see below), whose sum is σ = 87205662720. Its totient is φ = 70823026560.

The previous prime is 78721402369. The next prime is 78721402411. The reversal of 78721402387 is 78320412787.

It is a de Polignac number, because none of the positive numbers 2^k-78721402387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78721402387.

It is not an unprimeable number, because it can be changed into a prime (78721402327) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4033689 + ... + 4053157.

It is an arithmetic number, because the mean of its divisors is an integer number (2725176960).

Almost surely, 2^78721402387 is an apocalyptic number.

78721402387 is a deficient number, since it is larger than the sum of its proper divisors (8484260333).

78721402387 is a wasteful number, since it uses less digits than its factorization.

78721402387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19683.

The product of its (nonzero) digits is 1053696, while the sum is 49.

The spelling of 78721402387 in words is "seventy-eight billion, seven hundred twenty-one million, four hundred two thousand, three hundred eighty-seven".