21253234 has 4 divisors (see below), whose sum is σ = 31879854. Its totient is φ = 10626616.

The previous prime is 21253217. The next prime is 21253237. The reversal of 21253234 is 43235212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20223009 + 1030225 = 4497^2 + 1015^2 .

It is not an unprimeable number, because it can be changed into a prime (21253237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5313307 + ... + 5313310.

Almost surely, 2^21253234 is an apocalyptic number.

21253234 is a deficient number, since it is larger than the sum of its proper divisors (10626620).

21253234 is a wasteful number, since it uses less digits than its factorization.

21253234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10626619.

The product of its digits is 1440, while the sum is 22.

The square root of 21253234 is about 4610.1229918517. The cubic root of 21253234 is about 276.9969633052.

Adding to 21253234 its reverse (43235212), we get a palindrome (64488446).

The spelling of 21253234 in words is "twenty-one million, two hundred fifty-three thousand, two hundred thirty-four".