20516631 has 8 divisors (see below), whose sum is σ = 27389184. Its totient is φ = 13660920.

The previous prime is 20516609. The next prime is 20516681. The reversal of 20516631 is 13661502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20516631 - 2¹¹ = 20514583 is a prime.

It is a super-2 number, since 2×20516631² = 841864295180322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20516681) 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 7 ways as a sum of consecutive naturals, for example, 1021 + ... + 6486.

It is an arithmetic number, because the mean of its divisors is an integer number (3423648).

Almost surely, 2^20516631 is an apocalyptic number.

20516631 is a deficient number, since it is larger than the sum of its proper divisors (6872553).

20516631 is an equidigital number, since it uses as much as digits as its factorization.

20516631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8421.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20516631 is about 4529.5287834387. The cubic root of 20516631 is about 273.7591744387.

It can be divided in two parts, 205 and 16631, that added together give a triangular number (16836 = T₁₈₃).

The spelling of 20516631 in words is "twenty million, five hundred sixteen thousand, six hundred thirty-one".