21004252 has 12 divisors (see below), whose sum is σ = 37360456. Its totient is φ = 10329840.

The previous prime is 21004241. The next prime is 21004261. The reversal of 21004252 is 25240012.

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, 42798 + ... + 43285.

Almost surely, 2^21004252 is an apocalyptic number.

It is an amenable number.

21004252 is a deficient number, since it is larger than the sum of its proper divisors (16356204).

21004252 is a wasteful number, since it uses less digits than its factorization.

21004252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86148 (or 86146 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 21004252 is about 4583.0396027091. The cubic root of 21004252 is about 275.9110369301.

Adding to 21004252 its reverse (25240012), we get a palindrome (46244264).

The spelling of 21004252 in words is "twenty-one million, four thousand, two hundred fifty-two".