61578520 has 16 divisors (see below), whose sum is σ = 138551760. Its totient is φ = 24631392.

The previous prime is 61578511. The next prime is 61578523. The reversal of 61578520 is 2587516.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61578523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 769692 + ... + 769771.

It is an arithmetic number, because the mean of its divisors is an integer number (8659485).

Almost surely, 2^61578520 is an apocalyptic number.

It is an amenable number.

61578520 is an abundant number, since it is smaller than the sum of its proper divisors (76973240).

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

61578520 is a wasteful number, since it uses less digits than its factorization.

61578520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539474 (or 1539470 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 61578520 is about 7847.1982261187. The cubic root of 61578520 is about 394.8902541879.

The spelling of 61578520 in words is "sixty-one million, five hundred seventy-eight thousand, five hundred twenty".