78364521 has 12 divisors (see below), whose sum is σ = 113380800. Its totient is φ = 52156440.

The previous prime is 78364499. The next prime is 78364523. The reversal of 78364521 is 12546387.

78364521 is a `hidden beast` number, since 7 + 8 + 3 + 645 + 2 + 1 = 666.

It is not a de Polignac number, because 78364521 - 2⁷ = 78364393 is a prime.

It is a super-2 number, since 2×78364521² = 12281996303118882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78364523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1221 + ... + 12578.

It is an arithmetic number, because the mean of its divisors is an integer number (9448400).

Almost surely, 2^78364521 is an apocalyptic number.

It is an amenable number.

78364521 is a deficient number, since it is larger than the sum of its proper divisors (35016279).

78364521 is a wasteful number, since it uses less digits than its factorization.

78364521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14436 (or 14433 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 78364521 is about 8852.3737494527. The cubic root of 78364521 is about 427.9304211143.

The spelling of 78364521 in words is "seventy-eight million, three hundred sixty-four thousand, five hundred twenty-one".