21738234 has 16 divisors (see below), whose sum is σ = 49687488. Its totient is φ = 6210912.

The previous prime is 21738221. The next prime is 21738239. The reversal of 21738234 is 43283712.

It is not an unprimeable number, because it can be changed into a prime (21738239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 258747 + ... + 258830.

It is an arithmetic number, because the mean of its divisors is an integer number (3105468).

Almost surely, 2^21738234 is an apocalyptic number.

21738234 is an abundant number, since it is smaller than the sum of its proper divisors (27949254).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21738234 is a wasteful number, since it uses less digits than its factorization.

21738234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517589.

The product of its digits is 8064, while the sum is 30.

The square root of 21738234 is about 4662.4279082898. The cubic root of 21738234 is about 279.0881647345.

The spelling of 21738234 in words is "twenty-one million, seven hundred thirty-eight thousand, two hundred thirty-four".