21723022 has 4 divisors (see below), whose sum is σ = 32584536. Its totient is φ = 10861510.

The previous prime is 21723019. The next prime is 21723029. The reversal of 21723022 is 22032712.

It is a semiprime because it is the product of two primes.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21723029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5430754 + ... + 5430757.

It is an arithmetic number, because the mean of its divisors is an integer number (8146134).

Almost surely, 2^21723022 is an apocalyptic number.

21723022 is a deficient number, since it is larger than the sum of its proper divisors (10861514).

21723022 is a wasteful number, since it uses less digits than its factorization.

21723022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10861513.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 21723022 is about 4660.7962838983. The cubic root of 21723022 is about 279.0230493584.

Adding to 21723022 its reverse (22032712), we get a palindrome (43755734).

The spelling of 21723022 in words is "twenty-one million, seven hundred twenty-three thousand, twenty-two".