78398725 has 24 divisors (see below), whose sum is σ = 99982440. Its totient is φ = 60960000.

The previous prime is 78398717. The next prime is 78398737. The reversal of 78398725 is 52789387.

It can be written as a sum of positive squares in 12 ways, for example, as 10484644 + 67914081 = 3238^2 + 8241^2 .

It is not a de Polignac number, because 78398725 - 2³ = 78398717 is a prime.

It is a super-2 number, since 2×78398725² = 12292720163251250, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 153771 + ... + 154279.

It is an arithmetic number, because the mean of its divisors is an integer number (4165935).

Almost surely, 2^78398725 is an apocalyptic number.

It is an amenable number.

78398725 is a deficient number, since it is larger than the sum of its proper divisors (21583715).

78398725 is a wasteful number, since it uses less digits than its factorization.

78398725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681 (or 676 counting only the distinct ones).

The product of its digits is 846720, while the sum is 49.

The square root of 78398725 is about 8854.3054498927. The cubic root of 78398725 is about 427.9926720875.

The spelling of 78398725 in words is "seventy-eight million, three hundred ninety-eight thousand, seven hundred twenty-five".