12997581 has 4 divisors (see below), whose sum is σ = 17330112. Its totient is φ = 8665052.

The previous prime is 12997573. The next prime is 12997591. The reversal of 12997581 is 18579921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18579921 = 3 ⋅6193307.

It is a cyclic number.

It is not a de Polignac number, because 12997581 - 2³ = 12997573 is a prime.

It is a super-2 number, since 2×12997581² = 337874223703122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12997541) 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, 2166261 + ... + 2166266.

It is an arithmetic number, because the mean of its divisors is an integer number (4332528).

Almost surely, 2^12997581 is an apocalyptic number.

It is an amenable number.

12997581 is a deficient number, since it is larger than the sum of its proper divisors (4332531).

12997581 is an equidigital number, since it uses as much as digits as its factorization.

12997581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4332530.

The product of its digits is 45360, while the sum is 42.

The square root of 12997581 is about 3605.2158049138. The cubic root of 12997581 is about 235.1188835633.

The spelling of 12997581 in words is "twelve million, nine hundred ninety-seven thousand, five hundred eighty-one".