20812506 has 64 divisors (see below), whose sum is σ = 49545216. Its totient is φ = 5745600.

The previous prime is 20812483. The next prime is 20812511. The reversal of 20812506 is 60521802.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108871 + ... + 109061.

It is an arithmetic number, because the mean of its divisors is an integer number (774144).

Almost surely, 2^20812506 is an apocalyptic number.

20812506 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 20812506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24772608).

20812506 is an abundant number, since it is smaller than the sum of its proper divisors (28732710).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20812506 is a wasteful number, since it uses less digits than its factorization.

20812506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 20812506 is about 4562.0725553196. The cubic root of 20812506 is about 275.0688797158.

The spelling of 20812506 in words is "twenty million, eight hundred twelve thousand, five hundred six".