20261931 has 4 divisors (see below), whose sum is σ = 27015912. Its totient is φ = 13507952.

The previous prime is 20261929. The next prime is 20261947. The reversal of 20261931 is 13916202.

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 20261931 - 2¹ = 20261929 is a prime.

It is a super-2 number, since 2×20261931² = 821091695697522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20261911) 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, 3376986 + ... + 3376991.

It is an arithmetic number, because the mean of its divisors is an integer number (6753978).

Almost surely, 2^20261931 is an apocalyptic number.

20261931 is a deficient number, since it is larger than the sum of its proper divisors (6753981).

20261931 is an equidigital number, since it uses as much as digits as its factorization.

20261931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6753980.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 20261931 is about 4501.3254714584. The cubic root of 20261931 is about 272.6216094417.

The spelling of 20261931 in words is "twenty million, two hundred sixty-one thousand, nine hundred thirty-one".