20512131 has 4 divisors (see below), whose sum is σ = 27349512. Its totient is φ = 13674752.

The previous prime is 20512087. The next prime is 20512139. The reversal of 20512131 is 13121502.

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 20512131 - 2⁹ = 20511619 is a prime.

It is a super-2 number, since 2×20512131² = 841495036322322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20512131.

It is not an unprimeable number, because it can be changed into a prime (20512139) 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, 3418686 + ... + 3418691.

It is an arithmetic number, because the mean of its divisors is an integer number (6837378).

Almost surely, 2^20512131 is an apocalyptic number.

20512131 is a deficient number, since it is larger than the sum of its proper divisors (6837381).

20512131 is an equidigital number, since it uses as much as digits as its factorization.

20512131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6837380.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 20512131 is about 4529.0320157844. The cubic root of 20512131 is about 273.7391580535.

Adding to 20512131 its reverse (13121502), we get a palindrome (33633633).

The spelling of 20512131 in words is "twenty million, five hundred twelve thousand, one hundred thirty-one".