20215920 has 80 divisors (see below), whose sum is σ = 63245952. Its totient is φ = 5341440.

The previous prime is 20215883. The next prime is 20215967. The reversal of 20215920 is 2951202.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31119 + ... + 31761.

Almost surely, 2^20215920 is an apocalyptic number.

20215920 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 20215920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31622976).

20215920 is an abundant number, since it is smaller than the sum of its proper divisors (43030032).

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

20215920 is a wasteful number, since it uses less digits than its factorization.

20215920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 20215920 is about 4496.2117387863. The cubic root of 20215920 is about 272.4150957326.

The spelling of 20215920 in words is "twenty million, two hundred fifteen thousand, nine hundred twenty".