21243034 has 4 divisors (see below), whose sum is σ = 31864554. Its totient is φ = 10621516.

The previous prime is 21243023. The next prime is 21243049. The reversal of 21243034 is 43034212.

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., 15976009 + 5267025 = 3997^2 + 2295^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5310757 + ... + 5310760.

Almost surely, 2^21243034 is an apocalyptic number.

21243034 is a deficient number, since it is larger than the sum of its proper divisors (10621520).

21243034 is a wasteful number, since it uses less digits than its factorization.

21243034 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10621519.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 21243034 is about 4609.0165979306. The cubic root of 21243034 is about 276.9526434441.

Adding to 21243034 its reverse (43034212), we get a palindrome (64277246).

The spelling of 21243034 in words is "twenty-one million, two hundred forty-three thousand, thirty-four".