20647131 has 4 divisors (see below), whose sum is σ = 27529512. Its totient is φ = 13764752.

The previous prime is 20647117. The next prime is 20647139. The reversal of 20647131 is 13174602.

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 20647131 - 2¹⁰ = 20646107 is a prime.

It is a super-2 number, since 2×20647131² = 852608037062322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20647139) 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, 3441186 + ... + 3441191.

It is an arithmetic number, because the mean of its divisors is an integer number (6882378).

Almost surely, 2^20647131 is an apocalyptic number.

20647131 is a deficient number, since it is larger than the sum of its proper divisors (6882381).

20647131 is an equidigital number, since it uses as much as digits as its factorization.

20647131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6882380.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 20647131 is about 4543.9114207916. The cubic root of 20647131 is about 274.3383808449.

The spelling of 20647131 in words is "twenty million, six hundred forty-seven thousand, one hundred thirty-one".