78971825 has 6 divisors (see below), whose sum is σ = 97925094. Its totient is φ = 63177440.

The previous prime is 78971819. The next prime is 78971831. The reversal of 78971825 is 52817987.

It is an interprime number because it is at equal distance from previous prime (78971819) and next prime (78971831).

It can be written as a sum of positive squares in 3 ways, for example, as 17631601 + 61340224 = 4199^2 + 7832^2 .

It is not a de Polignac number, because 78971825 - 2¹² = 78967729 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 78971825.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1579412 + ... + 1579461.

It is an arithmetic number, because the mean of its divisors is an integer number (16320849).

Almost surely, 2^78971825 is an apocalyptic number.

It is an amenable number.

78971825 is a deficient number, since it is larger than the sum of its proper divisors (18953269).

78971825 is a wasteful number, since it uses less digits than its factorization.

78971825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3158883 (or 3158878 counting only the distinct ones).

The product of its digits is 282240, while the sum is 47.

The square root of 78971825 is about 8886.6093083920. The cubic root of 78971825 is about 429.0330263296.

The spelling of 78971825 in words is "seventy-eight million, nine hundred seventy-one thousand, eight hundred twenty-five".