78178520 has 48 divisors (see below), whose sum is σ = 204625440. Its totient is φ = 26803392.

The previous prime is 78178511. The next prime is 78178523. The reversal of 78178520 is 2587187.

It is a super-2 number, since 2×78178520² = 12223761978780800, which contains 22 as substring.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78178523) 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, 17984 + ... + 21903.

It is an arithmetic number, because the mean of its divisors is an integer number (4263030).

Almost surely, 2^78178520 is an apocalyptic number.

78178520 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78178520 is an abundant number, since it is smaller than the sum of its proper divisors (126446920).

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

78178520 is a wasteful number, since it uses less digits than its factorization.

78178520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39912 (or 39901 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 78178520 is about 8841.8617948937. The cubic root of 78178520 is about 427.5915834930.

The spelling of 78178520 in words is "seventy-eight million, one hundred seventy-eight thousand, five hundred twenty".