78149520 has 60 divisors (see below), whose sum is σ = 262454556. Its totient is φ = 20839680.

The previous prime is 78149509. The next prime is 78149551. The reversal of 78149520 is 2594187.

It can be written as a sum of positive squares in 2 ways, for example, as 51151104 + 26998416 = 7152^2 + 5196^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×78149520² = 12214694952460800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53551 + ... + 54990.

Almost surely, 2^78149520 is an apocalyptic number.

It is an amenable number.

78149520 is an abundant number, since it is smaller than the sum of its proper divisors (184305036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78149520 is a wasteful number, since it uses less digits than its factorization.

78149520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108560 (or 108551 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 78149520 is about 8840.2217166766. The cubic root of 78149520 is about 427.5387058419.

The spelling of 78149520 in words is "seventy-eight million, one hundred forty-nine thousand, five hundred twenty".