61138920 has 64 divisors (see below), whose sum is σ = 183942720. Its totient is φ = 16257024.

The previous prime is 61138901. The next prime is 61138933. The reversal of 61138920 is 2983116.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68799 + ... + 69681.

It is an arithmetic number, because the mean of its divisors is an integer number (2874105).

Almost surely, 2^61138920 is an apocalyptic number.

61138920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61138920 is an abundant number, since it is smaller than the sum of its proper divisors (122803800).

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

61138920 is a wasteful number, since it uses less digits than its factorization.

61138920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1474 (or 1470 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 61138920 is about 7819.1380599143. The cubic root of 61138920 is about 393.9483213589.

The spelling of 61138920 in words is "sixty-one million, one hundred thirty-eight thousand, nine hundred twenty".