78454521 has 32 divisors (see below), whose sum is σ = 121856000. Its totient is φ = 49824720.

The previous prime is 78454517. The next prime is 78454531. The reversal of 78454521 is 12545487.

78454521 is a `hidden beast` number, since 7 + 84 + 54 + 521 = 666.

It is not a de Polignac number, because 78454521 - 2² = 78454517 is a prime.

It is a super-2 number, since 2×78454521² = 12310223730678882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78454501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55380 + ... + 56778.

It is an arithmetic number, because the mean of its divisors is an integer number (3808000).

Almost surely, 2^78454521 is an apocalyptic number.

It is an amenable number.

78454521 is a deficient number, since it is larger than the sum of its proper divisors (43401479).

78454521 is a wasteful number, since it uses less digits than its factorization.

78454521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506 (or 1500 counting only the distinct ones).

The product of its digits is 44800, while the sum is 36.

The square root of 78454521 is about 8857.4556730474. The cubic root of 78454521 is about 428.0941814603.

The spelling of 78454521 in words is "seventy-eight million, four hundred fifty-four thousand, five hundred twenty-one".