61137920 has 44 divisors (see below), whose sum is σ = 146671644. Its totient is φ = 24453120.

The previous prime is 61137911. The next prime is 61137931. The reversal of 61137920 is 2973116.

It can be written as a sum of positive squares in 2 ways, for example, as 18939904 + 42198016 = 4352^2 + 6496^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 851 + ... + 11090.

Almost surely, 2^61137920 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 61137920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73335822).

61137920 is an abundant number, since it is smaller than the sum of its proper divisors (85533724).

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

61137920 is a wasteful number, since it uses less digits than its factorization.

61137920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11966 (or 11948 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 61137920 is about 7819.0741139856. The cubic root of 61137920 is about 393.9461735155.

The spelling of 61137920 in words is "sixty-one million, one hundred thirty-seven thousand, nine hundred twenty".