21923055 has 160 divisors (see below), whose sum is σ = 52968960. Its totient is φ = 8398080.

The previous prime is 21923023. The next prime is 21923059. The reversal of 21923055 is 55032912.

It is not a de Polignac number, because 21923055 - 2⁵ = 21923023 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21923059) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 592497 + ... + 592533.

It is an arithmetic number, because the mean of its divisors is an integer number (331056).

Almost surely, 2^21923055 is an apocalyptic number.

21923055 is an abundant number, since it is smaller than the sum of its proper divisors (31045905).

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

21923055 is a wasteful number, since it uses less digits than its factorization.

21923055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 82 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 21923055 is about 4682.2062107515. The cubic root of 21923055 is about 279.8768803945.

Adding to 21923055 its reverse (55032912), we get a palindrome (76955967).

The spelling of 21923055 in words is "twenty-one million, nine hundred twenty-three thousand, fifty-five".