78814521 has 12 divisors (see below), whose sum is σ = 114889060. Its totient is φ = 52060320.

The previous prime is 78814513. The next prime is 78814577. The reversal of 78814521 is 12541887.

It can be written as a sum of positive squares in 2 ways, for example, as 62726400 + 16088121 = 7920^2 + 4011^2 .

It is not a de Polignac number, because 78814521 - 2³ = 78814513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78814621) 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, 39190 + ... + 41151.

Almost surely, 2^78814521 is an apocalyptic number.

It is an amenable number.

78814521 is a deficient number, since it is larger than the sum of its proper divisors (36074539).

78814521 is a wasteful number, since it uses less digits than its factorization.

78814521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80456 (or 80453 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 78814521 is about 8877.7542768428. The cubic root of 78814521 is about 428.7479733122.

The spelling of 78814521 in words is "seventy-eight million, eight hundred fourteen thousand, five hundred twenty-one".