21940488 has 24 divisors (see below), whose sum is σ = 59422350. Its totient is φ = 7313472.

The previous prime is 21940487. The next prime is 21940511. The reversal of 21940488 is 88404912.

It can be written as a sum of positive squares in only one way, i.e., 11168964 + 10771524 = 3342^2 + 3282^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21940483) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 152293 + ... + 152436.

Almost surely, 2^21940488 is an apocalyptic number.

It is an amenable number.

21940488 is an abundant number, since it is smaller than the sum of its proper divisors (37481862).

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

21940488 is a wasteful number, since it uses less digits than its factorization.

21940488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304741 (or 304734 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 21940488 is about 4684.0674632204. The cubic root of 21940488 is about 279.9510458633.

The spelling of 21940488 in words is "twenty-one million, nine hundred forty thousand, four hundred eighty-eight".