61645566 has 32 divisors (see below), whose sum is σ = 129040128. Its totient is φ = 19595840.

The previous prime is 61645471. The next prime is 61645627. The reversal of 61645566 is 66554616.

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, 80626 + ... + 81386.

It is an arithmetic number, because the mean of its divisors is an integer number (4032504).

Almost surely, 2^61645566 is an apocalyptic number.

61645566 is an abundant number, since it is smaller than the sum of its proper divisors (67394562).

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

61645566 is a wasteful number, since it uses less digits than its factorization.

61645566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1376.

The product of its digits is 129600, while the sum is 39.

The square root of 61645566 is about 7851.4690345183. The cubic root of 61645566 is about 395.0335195611.

The spelling of 61645566 in words is "sixty-one million, six hundred forty-five thousand, five hundred sixty-six".