21523484 has 12 divisors (see below), whose sum is σ = 38284008. Its totient is φ = 10585200.

The previous prime is 21523433. The next prime is 21523499. The reversal of 21523484 is 48432512.

It is a happy number.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43862 + ... + 44349.

It is an arithmetic number, because the mean of its divisors is an integer number (3190334).

Almost surely, 2^21523484 is an apocalyptic number.

It is an amenable number.

21523484 is a deficient number, since it is larger than the sum of its proper divisors (16760524).

21523484 is a wasteful number, since it uses less digits than its factorization.

21523484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88276 (or 88274 counting only the distinct ones).

The product of its digits is 7680, while the sum is 29.

The square root of 21523484 is about 4639.3409014643. The cubic root of 21523484 is about 278.1660929729.

Adding to 21523484 its reverse (48432512), we get a palindrome (69955996).

The spelling of 21523484 in words is "twenty-one million, five hundred twenty-three thousand, four hundred eighty-four".