65631566 has 32 divisors (see below), whose sum is σ = 132185088. Its totient is φ = 23603040.

The previous prime is 65631563. The next prime is 65631571. The reversal of 65631566 is 66513656.

It is a super-2 number, since 2×65631566² = 8615004911224712, which contains 22 as substring.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65631563) 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, 14390 + ... + 18393.

It is an arithmetic number, because the mean of its divisors is an integer number (4130784).

Almost surely, 2^65631566 is an apocalyptic number.

65631566 is an abundant number, since it is smaller than the sum of its proper divisors (66553522).

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

65631566 is a wasteful number, since it uses less digits than its factorization.

65631566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32816.

The product of its digits is 97200, while the sum is 38.

The square root of 65631566 is about 8101.3311251917. The cubic root of 65631566 is about 403.3706134670.

The spelling of 65631566 in words is "sixty-five million, six hundred thirty-one thousand, five hundred sixty-six".