78398978972 has 24 divisors (see below), whose sum is σ = 142005195360. Its totient is φ = 37827513920.

The previous prime is 78398978857. The next prime is 78398978989. The reversal of 78398978972 is 27987989387.

It is a super-2 number, since 2×78398978972² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78398978893 and 78398978902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37697 + ... + 397767.

It is an arithmetic number, because the mean of its divisors is an integer number (5916883140).

Almost surely, 2^78398978972 is an apocalyptic number.

It is an amenable number.

78398978972 is a deficient number, since it is larger than the sum of its proper divisors (63606216388).

78398978972 is a wasteful number, since it uses less digits than its factorization.

78398978972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361981 (or 361979 counting only the distinct ones).

The product of its digits is 768144384, while the sum is 77.

The spelling of 78398978972 in words is "seventy-eight billion, three hundred ninety-eight million, nine hundred seventy-eight thousand, nine hundred seventy-two".