661152131 has 4 divisors (see below), whose sum is σ = 661205952. Its totient is φ = 661098312.

The previous prime is 661152127. The next prime is 661152137. The reversal of 661152131 is 131251166.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 661152131 - 2² = 661152127 is a prime.

It is a super-2 number, since 2×661152131² = 874244280651682322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661152131.

It is not an unprimeable number, because it can be changed into a prime (661152137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1550 + ... + 36396.

It is an arithmetic number, because the mean of its divisors is an integer number (165301488).

Almost surely, 2^661152131 is an apocalyptic number.

661152131 is a deficient number, since it is larger than the sum of its proper divisors (53821).

661152131 is a wasteful number, since it uses less digits than its factorization.

661152131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53820.

The product of its digits is 1080, while the sum is 26.

The square root of 661152131 is about 25712.8786992044. The cubic root of 661152131 is about 871.1650973133.

The spelling of 661152131 in words is "six hundred sixty-one million, one hundred fifty-two thousand, one hundred thirty-one".