13997531 has 4 divisors (see below), whose sum is σ = 14189352. Its totient is φ = 13805712.

The previous prime is 13997519. The next prime is 13997537. The reversal of 13997531 is 13579931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13579931 = 859 ⋅15809.

It is a cyclic number.

It is not a de Polignac number, because 13997531 - 2¹⁴ = 13981147 is a prime.

It is a super-2 number, since 2×13997531² = 391861748191922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13997537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95801 + ... + 95946.

It is an arithmetic number, because the mean of its divisors is an integer number (3547338).

Almost surely, 2^13997531 is an apocalyptic number.

13997531 is a deficient number, since it is larger than the sum of its proper divisors (191821).

13997531 is an equidigital number, since it uses as much as digits as its factorization.

13997531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191820.

The product of its digits is 25515, while the sum is 38.

The square root of 13997531 is about 3741.3274382230. The cubic root of 13997531 is about 241.0000573911. Note that the first 4 decimals are identical.

The spelling of 13997531 in words is "thirteen million, nine hundred ninety-seven thousand, five hundred thirty-one".