78158520 has 384 divisors, whose sum is σ = 311351040. Its totient is φ = 17418240.

The previous prime is 78158513. The next prime is 78158557. The reversal of 78158520 is 2585187.

78158520 is a `hidden beast` number, since 7 + 81 + 58 + 520 = 666.

It is a super-2 number, since 2×78158520² = 12217508497180800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1817619 + ... + 1817661.

It is an arithmetic number, because the mean of its divisors is an integer number (810810).

Almost surely, 2^78158520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78158520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155675520).

78158520 is an abundant number, since it is smaller than the sum of its proper divisors (233192520).

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

78158520 is a wasteful number, since it uses less digits than its factorization.

78158520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The square root of 78158520 is about 8840.7307390283. The cubic root of 78158520 is about 427.5551175471. Note that the first 3 decimals are identical.

The spelling of 78158520 in words is "seventy-eight million, one hundred fifty-eight thousand, five hundred twenty".