21308234 has 16 divisors (see below), whose sum is σ = 33734880. Its totient is φ = 10066320.

The previous prime is 21308219. The next prime is 21308299. The reversal of 21308234 is 43280312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25544 + ... + 26364.

It is an arithmetic number, because the mean of its divisors is an integer number (2108430).

Almost surely, 2^21308234 is an apocalyptic number.

21308234 is a deficient number, since it is larger than the sum of its proper divisors (12426646).

21308234 is a wasteful number, since it uses less digits than its factorization.

21308234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1525.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21308234 is about 4616.0842713278. The cubic root of 21308234 is about 277.2356988951.

Adding to 21308234 its reverse (43280312), we get a palindrome (64588546).

The spelling of 21308234 in words is "twenty-one million, three hundred eight thousand, two hundred thirty-four".