79878999987897 has 64 divisors (see below), whose sum is σ = 116874229570560. Its totient is φ = 48126442291200.

The previous prime is 79878999987889. The next prime is 79878999987901.

79878999987897 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 79878999987897 - 2³ = 79878999987889 is a prime.

It is a super-2 number, since 2×79878999987897² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (79878999987797) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6334067122 + ... + 6334079732.

It is an arithmetic number, because the mean of its divisors is an integer number (1826159837040).

Almost surely, 2^{79878999987897} is an apocalyptic number.

It is an amenable number.

79878999987897 is a deficient number, since it is larger than the sum of its proper divisors (36995229582663).

79878999987897 is a wasteful number, since it uses less digits than its factorization.

79878999987897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14534.

The product of its digits is 5226454388736, while the sum is 114.

The spelling of 79878999987897 in words is "seventy-nine trillion, eight hundred seventy-eight billion, nine hundred ninety-nine million, nine hundred eighty-seven thousand, eight hundred ninety-seven".