78921725 has 12 divisors (see below), whose sum is σ = 103014240. Its totient is φ = 59814000.

The previous prime is 78921721. The next prime is 78921743. The reversal of 78921725 is 52712987.

It is not a de Polignac number, because 78921725 - 2² = 78921721 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78921721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82601 + ... + 83550.

It is an arithmetic number, because the mean of its divisors is an integer number (8584520).

Almost surely, 2^78921725 is an apocalyptic number.

It is an amenable number.

78921725 is a deficient number, since it is larger than the sum of its proper divisors (24092515).

78921725 is a wasteful number, since it uses less digits than its factorization.

78921725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166180 (or 166175 counting only the distinct ones).

The product of its digits is 70560, while the sum is 41.

The square root of 78921725 is about 8883.7900132770. The cubic root of 78921725 is about 428.9422804565.

The spelling of 78921725 in words is "seventy-eight million, nine hundred twenty-one thousand, seven hundred twenty-five".