21740234 has 8 divisors (see below), whose sum is σ = 32689440. Its totient is φ = 10843756.

The previous prime is 21740233. The next prime is 21740239. The reversal of 21740234 is 43204712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21740231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12134 + ... + 13809.

It is an arithmetic number, because the mean of its divisors is an integer number (4086180).

Almost surely, 2^21740234 is an apocalyptic number.

21740234 is a deficient number, since it is larger than the sum of its proper divisors (10949206).

21740234 is a wasteful number, since it uses less digits than its factorization.

21740234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26364.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21740234 is about 4662.6423838849. The cubic root of 21740234 is about 279.0967235287.

Adding to 21740234 its reverse (43204712), we get a palindrome (64944946).

The spelling of 21740234 in words is "twenty-one million, seven hundred forty thousand, two hundred thirty-four".