21349924 has 24 divisors (see below), whose sum is σ = 38229408. Its totient is φ = 10430400.

The previous prime is 21349907. The next prime is 21349963. The reversal of 21349924 is 42994312.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 21349924.

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, 35224 + ... + 35824.

It is an arithmetic number, because the mean of its divisors is an integer number (1592892).

Almost surely, 2^21349924 is an apocalyptic number.

It is an amenable number.

21349924 is a deficient number, since it is larger than the sum of its proper divisors (16879484).

21349924 is a wasteful number, since it uses less digits than its factorization.

21349924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795 (or 793 counting only the distinct ones).

The product of its digits is 15552, while the sum is 34.

The square root of 21349924 is about 4620.5977968224. The cubic root of 21349924 is about 277.4163868970.

The spelling of 21349924 in words is "twenty-one million, three hundred forty-nine thousand, nine hundred twenty-four".