20436931 has 4 divisors (see below), whose sum is σ = 20451600. Its totient is φ = 20422264.

The previous prime is 20436929. The next prime is 20436937. The reversal of 20436931 is 13963402.

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 20436931 - 2¹ = 20436929 is a prime.

It is a super-2 number, since 2×20436931² = 835336297397522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20436931.

It is not an unprimeable number, because it can be changed into a prime (20436937) 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, 4996 + ... + 8113.

It is an arithmetic number, because the mean of its divisors is an integer number (5112900).

Almost surely, 2^20436931 is an apocalyptic number.

20436931 is a deficient number, since it is larger than the sum of its proper divisors (14669).

20436931 is a wasteful number, since it uses less digits than its factorization.

20436931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14668.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 20436931 is about 4520.7223980245. The cubic root of 20436931 is about 273.4042279255.

The spelling of 20436931 in words is "twenty million, four hundred thirty-six thousand, nine hundred thirty-one".