21702124 has 12 divisors (see below), whose sum is σ = 38048584. Its totient is φ = 10831104.

The previous prime is 21702103. The next prime is 21702157. The reversal of 21702124 is 42120712.

It is a happy number.

It is a super-2 number, since 2×21702124² = 941964372222752, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2394 + ... + 7009.

Almost surely, 2^21702124 is an apocalyptic number.

It is an amenable number.

21702124 is a deficient number, since it is larger than the sum of its proper divisors (16346460).

21702124 is a wasteful number, since it uses less digits than its factorization.

21702124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9984 (or 9982 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 21702124 is about 4658.5538528603. The cubic root of 21702124 is about 278.9335453206.

Adding to 21702124 its reverse (42120712), we get a palindrome (63822836).

The spelling of 21702124 in words is "twenty-one million, seven hundred two thousand, one hundred twenty-four".