61681920 has 72 divisors (see below), whose sum is σ = 197008896. Its totient is φ = 16447488.

The previous prime is 61681913. The next prime is 61681931. The reversal of 61681920 is 2918616.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4192 + ... + 11871.

Almost surely, 2^61681920 is an apocalyptic number.

61681920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61681920 is an abundant number, since it is smaller than the sum of its proper divisors (135326976).

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

61681920 is a wasteful number, since it uses less digits than its factorization.

61681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16087 (or 16073 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 61681920 is about 7853.7838014552. The cubic root of 61681920 is about 395.1111581618. Note that the first 4 decimals are identical.

The spelling of 61681920 in words is "sixty-one million, six hundred eighty-one thousand, nine hundred twenty".