21358252 has 6 divisors (see below), whose sum is σ = 37376948. Its totient is φ = 10679124.

The previous prime is 21358247. The next prime is 21358277. The reversal of 21358252 is 25285312.

It is a self number, because there is not a number n which added to its sum of digits gives 21358252.

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 as a sum of consecutive naturals, namely, 2669778 + ... + 2669785.

Almost surely, 2^21358252 is an apocalyptic number.

It is an amenable number.

21358252 is a deficient number, since it is larger than the sum of its proper divisors (16018696).

21358252 is a wasteful number, since it uses less digits than its factorization.

21358252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5339567 (or 5339565 counting only the distinct ones).

The product of its digits is 4800, while the sum is 28.

The square root of 21358252 is about 4621.4988910526. The cubic root of 21358252 is about 277.4524529635.

The spelling of 21358252 in words is "twenty-one million, three hundred fifty-eight thousand, two hundred fifty-two".