21927157 has 12 divisors (see below), whose sum is σ = 25891680. Its totient is φ = 18511416.

The previous prime is 21927151. The next prime is 21927181. The reversal of 21927157 is 75172912.

It is not a de Polignac number, because 21927157 - 2⁷ = 21927029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21927151) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57 + ... + 6622.

It is an arithmetic number, because the mean of its divisors is an integer number (2157640).

Almost surely, 2^21927157 is an apocalyptic number.

It is an amenable number.

21927157 is a deficient number, since it is larger than the sum of its proper divisors (3964523).

21927157 is an equidigital number, since it uses as much as digits as its factorization.

21927157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6760 (or 6753 counting only the distinct ones).

The product of its digits is 8820, while the sum is 34.

The square root of 21927157 is about 4682.6442316281. The cubic root of 21927157 is about 279.8943351298.

The spelling of 21927157 in words is "twenty-one million, nine hundred twenty-seven thousand, one hundred fifty-seven".