20137531 has 4 divisors (see below), whose sum is σ = 20184472. Its totient is φ = 20090592.

The previous prime is 20137487. The next prime is 20137541. The reversal of 20137531 is 13573102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20137531 - 2¹³ = 20129339 is a prime.

It is a super-2 number, since 2×20137531² = 811040309551922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20137541) 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, 22821 + ... + 23686.

It is an arithmetic number, because the mean of its divisors is an integer number (5046118).

Almost surely, 2^20137531 is an apocalyptic number.

20137531 is a deficient number, since it is larger than the sum of its proper divisors (46941).

20137531 is an equidigital number, since it uses as much as digits as its factorization.

20137531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46940.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 20137531 is about 4487.4860445465. The cubic root of 20137531 is about 272.0625351818.

The spelling of 20137531 in words is "twenty million, one hundred thirty-seven thousand, five hundred thirty-one".