78534561 has 16 divisors (see below), whose sum is σ = 120369024. Its totient is φ = 44615424.

The previous prime is 78534553. The next prime is 78534569. The reversal of 78534561 is 16543587.

It is an interprime number because it is at equal distance from previous prime (78534553) and next prime (78534569).

It is not a de Polignac number, because 78534561 - 2³ = 78534553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78534569) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7176 + ... + 14441.

It is an arithmetic number, because the mean of its divisors is an integer number (7523064).

Almost surely, 2^78534561 is an apocalyptic number.

It is an amenable number.

78534561 is a deficient number, since it is larger than the sum of its proper divisors (41834463).

78534561 is a wasteful number, since it uses less digits than its factorization.

78534561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21800.

The product of its digits is 100800, while the sum is 39.

The square root of 78534561 is about 8861.9727487733. The cubic root of 78534561 is about 428.2397138107.

The spelling of 78534561 in words is "seventy-eight million, five hundred thirty-four thousand, five hundred sixty-one".