61566140 has 24 divisors (see below), whose sum is σ = 129489360. Its totient is φ = 24588288.

The previous prime is 61566139. The next prime is 61566157. The reversal of 61566140 is 4166516.

It is a congruent number.

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, 13379 + ... + 17381.

It is an arithmetic number, because the mean of its divisors is an integer number (5395390).

Almost surely, 2^61566140 is an apocalyptic number.

It is an amenable number.

61566140 is an abundant number, since it is smaller than the sum of its proper divisors (67923220).

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

61566140 is a wasteful number, since it uses less digits than its factorization.

61566140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4781 (or 4779 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 61566140 is about 7846.4093698965. The cubic root of 61566140 is about 394.8637889584.

The spelling of 61566140 in words is "sixty-one million, five hundred sixty-six thousand, one hundred forty".