21925988 has 48 divisors (see below), whose sum is σ = 47142144. Its totient is φ = 8709120.

The previous prime is 21925987. The next prime is 21925997. The reversal of 21925988 is 88952912.

It is a super-2 number, since 2×21925988² = 961497899552288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21925987) 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, 34433 + ... + 35063.

It is an arithmetic number, because the mean of its divisors is an integer number (982128).

Almost surely, 2^21925988 is an apocalyptic number.

21925988 is a gapful number since it is divisible by the number (28) 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 21925988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23571072).

21925988 is an abundant number, since it is smaller than the sum of its proper divisors (25216156).

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

21925988 is a wasteful number, since it uses less digits than its factorization.

21925988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732 (or 730 counting only the distinct ones).

The product of its digits is 103680, while the sum is 44.

The square root of 21925988 is about 4682.5194073276. The cubic root of 21925988 is about 279.8893610499.

The spelling of 21925988 in words is "twenty-one million, nine hundred twenty-five thousand, nine hundred eighty-eight".