131222661 has 16 divisors (see below), whose sum is σ = 177316800. Its totient is φ = 86313600.

The previous prime is 131222657. The next prime is 131222669. The reversal of 131222661 is 166222131.

It is not a de Polignac number, because 131222661 - 2² = 131222657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131222669) 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 15 ways as a sum of consecutive naturals, for example, 71961 + ... + 73761.

It is an arithmetic number, because the mean of its divisors is an integer number (11082300).

Almost surely, 2^131222661 is an apocalyptic number.

It is an amenable number.

131222661 is a deficient number, since it is larger than the sum of its proper divisors (46094139).

131222661 is a wasteful number, since it uses less digits than its factorization.

131222661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2116.

The product of its digits is 864, while the sum is 24.

The square root of 131222661 is about 11455.2460034693. The cubic root of 131222661 is about 508.1628905477.

Adding to 131222661 its reverse (166222131), we get a palindrome (297444792).

The spelling of 131222661 in words is "one hundred thirty-one million, two hundred twenty-two thousand, six hundred sixty-one".