20894531 has 8 divisors (see below), whose sum is σ = 24367200. Its totient is φ = 17909304.

The previous prime is 20894501. The next prime is 20894551. The reversal of 20894531 is 13549802.

It is a de Polignac number, because none of the positive numbers 2^k-20894531 is a prime.

It is a super-2 number, since 2×20894531² = 873162851419922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20894501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30116 + ... + 30801.

It is an arithmetic number, because the mean of its divisors is an integer number (3045900).

Almost surely, 2^20894531 is an apocalyptic number.

20894531 is a deficient number, since it is larger than the sum of its proper divisors (3472669).

20894531 is an frugal number, since it uses more digits than its factorization.

20894531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60938 (or 60924 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 20894531 is about 4571.0535984606. The cubic root of 20894531 is about 275.4297676822.

The spelling of 20894531 in words is "twenty million, eight hundred ninety-four thousand, five hundred thirty-one".