78921012987 has 32 divisors (see below), whose sum is σ = 120199411200. Its totient is φ = 51141111264.

The previous prime is 78921012977. The next prime is 78921013021.

78921012987 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 78921012987 - 2⁴ = 78921012971 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (78921012977) 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, 979218 + ... + 1056744.

It is an arithmetic number, because the mean of its divisors is an integer number (3756231600).

Almost surely, 2^78921012987 is an apocalyptic number.

78921012987 is a deficient number, since it is larger than the sum of its proper divisors (41278398213).

78921012987 is a wasteful number, since it uses less digits than its factorization.

78921012987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78592 (or 78586 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 54.

The spelling of 78921012987 in words is "seventy-eight billion, nine hundred twenty-one million, twelve thousand, nine hundred eighty-seven".