61531860 has 48 divisors (see below), whose sum is σ = 185544576. Its totient is φ = 15146112.

The previous prime is 61531843. The next prime is 61531871. The reversal of 61531860 is 6813516.

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

It is a congruent number.

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, 38664 + ... + 40223.

It is an arithmetic number, because the mean of its divisors is an integer number (3865512).

Almost surely, 2^61531860 is an apocalyptic number.

61531860 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61531860 is an abundant number, since it is smaller than the sum of its proper divisors (124012716).

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

61531860 is a wasteful number, since it uses less digits than its factorization.

61531860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78912 (or 78910 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 61531860 is about 7844.2246270744. The cubic root of 61531860 is about 394.7904886901.

The spelling of 61531860 in words is "sixty-one million, five hundred thirty-one thousand, eight hundred sixty".