20925216 has 192 divisors, whose sum is σ = 69431040. Its totient is φ = 6158592.

The previous prime is 20925209. The next prime is 20925263. The reversal of 20925216 is 61252902.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 20925216.

It is a congruent 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, 909781 + ... + 909803.

It is an arithmetic number, because the mean of its divisors is an integer number (361620).

Almost surely, 2^20925216 is an apocalyptic number.

20925216 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20925216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34715520).

20925216 is an abundant number, since it is smaller than the sum of its proper divisors (48505824).

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

20925216 is an equidigital number, since it uses as much as digits as its factorization.

20925216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20925216 is about 4574.4088142622. The cubic root of 20925216 is about 275.5645306746.

It can be divided in two parts, 209 and 25216, that added together give a triangular number (25425 = T₂₂₅).

The spelling of 20925216 in words is "twenty million, nine hundred twenty-five thousand, two hundred sixteen".