21923208 has 24 divisors (see below), whose sum is σ = 59375550. Its totient is φ = 7307712.

The previous prime is 21923179. The next prime is 21923227. The reversal of 21923208 is 80232912.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21511044 + 412164 = 4638^2 + 642^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21923208² = 961254098022528, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 152173 + ... + 152316.

Almost surely, 2^21923208 is an apocalyptic number.

It is an amenable number.

21923208 is an abundant number, since it is smaller than the sum of its proper divisors (37452342).

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

21923208 is a wasteful number, since it uses less digits than its factorization.

21923208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304501 (or 304494 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21923208 is about 4682.2225491747. Note that the first 3 decimals coincide. The cubic root of 21923208 is about 279.8775314756.

The spelling of 21923208 in words is "twenty-one million, nine hundred twenty-three thousand, two hundred eight".