61665231 has 32 divisors (see below), whose sum is σ = 89653248. Its totient is φ = 37588320.

The previous prime is 61665221. The next prime is 61665283. The reversal of 61665231 is 13256616.

It is not a de Polignac number, because 61665231 - 2⁶ = 61665167 is a prime.

It is a super-2 number, since 2×61665231² = 7605201428566722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61665221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 271540 + ... + 271766.

It is an arithmetic number, because the mean of its divisors is an integer number (2801664).

Almost surely, 2^61665231 is an apocalyptic number.

61665231 is a deficient number, since it is larger than the sum of its proper divisors (27988017).

61665231 is a wasteful number, since it uses less digits than its factorization.

61665231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411.

The product of its digits is 6480, while the sum is 30.

The square root of 61665231 is about 7852.7212480770. The cubic root of 61665231 is about 395.0755204638.

The spelling of 61665231 in words is "sixty-one million, six hundred sixty-five thousand, two hundred thirty-one".