61615820 has 48 divisors (see below), whose sum is σ = 156582720. Its totient is φ = 19881984.

The previous prime is 61615789. The next prime is 61615823. The reversal of 61615820 is 2851616.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (61615823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10565 + ... + 15324.

It is an arithmetic number, because the mean of its divisors is an integer number (3262140).

Almost surely, 2^61615820 is an apocalyptic number.

It is an amenable number.

61615820 is an abundant number, since it is smaller than the sum of its proper divisors (94966900).

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

61615820 is a wasteful number, since it uses less digits than its factorization.

61615820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25922 (or 25920 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 61615820 is about 7849.5745107617. The cubic root of 61615820 is about 394.9699704779.

The spelling of 61615820 in words is "sixty-one million, six hundred fifteen thousand, eight hundred twenty".