61666131 has 8 divisors (see below), whose sum is σ = 82324944. Its totient is φ = 41059040.

The previous prime is 61666117. The next prime is 61666141. The reversal of 61666131 is 13166616.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61666131 - 2⁶ = 61666067 is a prime.

It is a super-2 number, since 2×61666131² = 7605423425018322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61666141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10056 + ... + 14981.

It is an arithmetic number, because the mean of its divisors is an integer number (10290618).

Almost surely, 2^61666131 is an apocalyptic number.

61666131 is a deficient number, since it is larger than the sum of its proper divisors (20658813).

61666131 is a wasteful number, since it uses less digits than its factorization.

61666131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25861.

The product of its digits is 3888, while the sum is 30.

The square root of 61666131 is about 7852.7785528436. The cubic root of 61666131 is about 395.0774424883.

The spelling of 61666131 in words is "sixty-one million, six hundred sixty-six thousand, one hundred thirty-one".