21722534 has 16 divisors (see below), whose sum is σ = 34201440. Its totient is φ = 10327680.

The previous prime is 21722531. The next prime is 21722543. The reversal of 21722534 is 43522712.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722531) 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, 7022 + ... + 9630.

It is an arithmetic number, because the mean of its divisors is an integer number (2137590).

Almost surely, 2^21722534 is an apocalyptic number.

21722534 is a deficient number, since it is larger than the sum of its proper divisors (12478906).

21722534 is a wasteful number, since it uses less digits than its factorization.

21722534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2815.

The product of its digits is 3360, while the sum is 26.

The square root of 21722534 is about 4660.7439320349. The cubic root of 21722534 is about 279.0209599580.

The spelling of 21722534 in words is "twenty-one million, seven hundred twenty-two thousand, five hundred thirty-four".