61566620 has 48 divisors (see below), whose sum is σ = 134400000. Its totient is φ = 23664960.

The previous prime is 61566613. The next prime is 61566643. The reversal of 61566620 is 2666516.

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, 123131 + ... + 123629.

It is an arithmetic number, because the mean of its divisors is an integer number (2800000).

Almost surely, 2^61566620 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 61566620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67200000).

61566620 is an abundant number, since it is smaller than the sum of its proper divisors (72833380).

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

61566620 is a wasteful number, since it uses less digits than its factorization.

61566620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738 (or 736 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 61566620 is about 7846.4399570761. The cubic root of 61566620 is about 394.8648151400.

The spelling of 61566620 in words is "sixty-one million, five hundred sixty-six thousand, six hundred twenty".