131221365 has 32 divisors (see below), whose sum is σ = 230414976. Its totient is φ = 63240960.

The previous prime is 131221339. The next prime is 131221379. The reversal of 131221365 is 563122131.

It is not a de Polignac number, because 131221365 - 2⁶ = 131221301 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26247 + ... + 30843.

It is an arithmetic number, because the mean of its divisors is an integer number (7200468).

Almost surely, 2^131221365 is an apocalyptic number.

131221365 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

131221365 is a deficient number, since it is larger than the sum of its proper divisors (99193611).

131221365 is a wasteful number, since it uses less digits than its factorization.

131221365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4789.

The product of its digits is 1080, while the sum is 24.

The square root of 131221365 is about 11455.1894353607. The cubic root of 131221365 is about 508.1612176118.

Adding to 131221365 its reverse (563122131), we get a palindrome (694343496).

The spelling of 131221365 in words is "one hundred thirty-one million, two hundred twenty-one thousand, three hundred sixty-five".