20911825 has 36 divisors (see below), whose sum is σ = 29553664. Its totient is φ = 14652000.

The previous prime is 20911823. The next prime is 20911867. The reversal of 20911825 is 52811902.

It is not a de Polignac number, because 20911825 - 2¹ = 20911823 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20911793 and 20911802.

It is not an unprimeable number, because it can be changed into a prime (20911823) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 93664 + ... + 93886.

Almost surely, 2^20911825 is an apocalyptic number.

20911825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20911825 is a deficient number, since it is larger than the sum of its proper divisors (8641839).

20911825 is a wasteful number, since it uses less digits than its factorization.

20911825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 20911825 is about 4572.9448936107. The cubic root of 20911825 is about 275.5057360277.

It can be divided in two parts, 20911 and 825, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 20911825 in words is "twenty million, nine hundred eleven thousand, eight hundred twenty-five".