20904960 has 88 divisors (see below), whose sum is σ = 66912336. Its totient is φ = 5570560.

The previous prime is 20904941. The next prime is 20904971. The reversal of 20904960 is 6940902.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14680 + ... + 16040.

Almost surely, 2^20904960 is an apocalyptic number.

20904960 is a gapful number since it is divisible by the number (20) 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 20904960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33456168).

20904960 is an abundant number, since it is smaller than the sum of its proper divisors (46007376).

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

20904960 is a wasteful number, since it uses less digits than its factorization.

20904960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389 (or 1371 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 20904960 is about 4572.1942215965. The cubic root of 20904960 is about 275.4755847635.

The spelling of 20904960 in words is "twenty million, nine hundred four thousand, nine hundred sixty".