21920151 has 16 divisors (see below), whose sum is σ = 32198400. Its totient is φ = 13153920.

The previous prime is 21920141. The next prime is 21920177. The reversal of 21920151 is 15102912.

It is not a de Polignac number, because 21920151 - 2⁷ = 21920023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21920141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175 + ... + 6623.

It is an arithmetic number, because the mean of its divisors is an integer number (2012400).

Almost surely, 2^21920151 is an apocalyptic number.

21920151 is a deficient number, since it is larger than the sum of its proper divisors (10278249).

21920151 is a wasteful number, since it uses less digits than its factorization.

21920151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6566.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 21920151 is about 4681.8960902609. The cubic root of 21920151 is about 279.8645220446.

The spelling of 21920151 in words is "twenty-one million, nine hundred twenty thousand, one hundred fifty-one".