21142504 has 16 divisors (see below), whose sum is σ = 39910500. Its totient is φ = 10499712.

The previous prime is 21142493. The next prime is 21142529. The reversal of 21142504 is 40524112.

It can be written as a sum of positive squares in 2 ways, for example, as 21141604 + 900 = 4598^2 + 30^2 .

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, 7677 + ... + 10060.

Almost surely, 2^21142504 is an apocalyptic number.

It is an amenable number.

21142504 is a deficient number, since it is larger than the sum of its proper divisors (18767996).

21142504 is a wasteful number, since it uses less digits than its factorization.

21142504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17892 (or 17888 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 21142504 is about 4598.0978675970. The cubic root of 21142504 is about 276.5150712224.

Adding to 21142504 its reverse (40524112), we get a palindrome (61666616).

The spelling of 21142504 in words is "twenty-one million, one hundred forty-two thousand, five hundred four".