21542252 has 12 divisors (see below), whose sum is σ = 38230416. Its totient is φ = 10619280.

The previous prime is 21542233. The next prime is 21542263. The reversal of 21542252 is 25224512.

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, 37643 + ... + 38210.

It is an arithmetic number, because the mean of its divisors is an integer number (3185868).

Almost surely, 2^21542252 is an apocalyptic number.

It is an amenable number.

21542252 is a deficient number, since it is larger than the sum of its proper divisors (16688164).

21542252 is a wasteful number, since it uses less digits than its factorization.

21542252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75928 (or 75926 counting only the distinct ones).

The product of its digits is 1600, while the sum is 23.

The square root of 21542252 is about 4641.3631618308. The cubic root of 21542252 is about 278.2469210357.

Adding to 21542252 its reverse (25224512), we get a palindrome (46766764).

The spelling of 21542252 in words is "twenty-one million, five hundred forty-two thousand, two hundred fifty-two".