21753442 has 16 divisors (see below), whose sum is σ = 35148960. Its totient is φ = 10063872.

The previous prime is 21753419. The next prime is 21753533. The reversal of 21753442 is 24435712.

It is a self number, because there is not a number n which added to its sum of digits gives 21753442.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5023 + ... + 8290.

It is an arithmetic number, because the mean of its divisors is an integer number (2196810).

Almost surely, 2^21753442 is an apocalyptic number.

21753442 is a deficient number, since it is larger than the sum of its proper divisors (13395518).

21753442 is a wasteful number, since it uses less digits than its factorization.

21753442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13377.

The product of its digits is 6720, while the sum is 28.

The square root of 21753442 is about 4664.0585330804. The cubic root of 21753442 is about 279.1532326299.

The spelling of 21753442 in words is "twenty-one million, seven hundred fifty-three thousand, four hundred forty-two".