20995920 has 180 divisors, whose sum is σ = 77825748. Its totient is φ = 5068800.

The previous prime is 20995903. The next prime is 20995939. The reversal of 20995920 is 2959902.

It can be written as a sum of positive squares in 2 ways, for example, as 11778624 + 9217296 = 3432^2 + 3036^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 87000 + ... + 87240.

Almost surely, 2^20995920 is an apocalyptic number.

20995920 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 20995920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38912874).

20995920 is an abundant number, since it is smaller than the sum of its proper divisors (56829828).

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

20995920 is a wasteful number, since it uses less digits than its factorization.

20995920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 20995920 is about 4582.1305088354. The cubic root of 20995920 is about 275.8745491624.

The spelling of 20995920 in words is "twenty million, nine hundred ninety-five thousand, nine hundred twenty".