21145234 has 48 divisors (see below), whose sum is σ = 37920960. Its totient is φ = 8808800.

The previous prime is 21145213. The next prime is 21145249. The reversal of 21145234 is 43254112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 161349 + ... + 161479.

It is an arithmetic number, because the mean of its divisors is an integer number (790020).

Almost surely, 2^21145234 is an apocalyptic number.

21145234 is a deficient number, since it is larger than the sum of its proper divisors (16775726).

21145234 is a wasteful number, since it uses less digits than its factorization.

21145234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 196 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 21145234 is about 4598.3947198995. The cubic root of 21145234 is about 276.5269722671.

Adding to 21145234 its reverse (43254112), we get a palindrome (64399346).

The spelling of 21145234 in words is "twenty-one million, one hundred forty-five thousand, two hundred thirty-four".