21284234 has 4 divisors (see below), whose sum is σ = 31926354. Its totient is φ = 10642116.

The previous prime is 21284227. The next prime is 21284243. The reversal of 21284234 is 43248212.

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., 17850625 + 3433609 = 4225^2 + 1853^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5321057 + ... + 5321060.

Almost surely, 2^21284234 is an apocalyptic number.

21284234 is a deficient number, since it is larger than the sum of its proper divisors (10642120).

21284234 is a wasteful number, since it uses less digits than its factorization.

21284234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10642119.

The product of its digits is 3072, while the sum is 26.

The square root of 21284234 is about 4613.4839329947. The cubic root of 21284234 is about 277.1315739451.

The spelling of 21284234 in words is "twenty-one million, two hundred eighty-four thousand, two hundred thirty-four".