21723122 has 8 divisors (see below), whose sum is σ = 32653056. Its totient is φ = 10838772.

The previous prime is 21723113. The next prime is 21723167. The reversal of 21723122 is 22132712.

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

It is a junction number, because it is equal to n+sod(n) for n = 21723094 and 21723103.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10178 + ... + 12125.

It is an arithmetic number, because the mean of its divisors is an integer number (4081632).

Almost surely, 2^21723122 is an apocalyptic number.

21723122 is a deficient number, since it is larger than the sum of its proper divisors (10929934).

21723122 is a wasteful number, since it uses less digits than its factorization.

21723122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22792.

The product of its digits is 336, while the sum is 20.

The square root of 21723122 is about 4660.8070116665. The cubic root of 21723122 is about 279.0234775103.

Adding to 21723122 its reverse (22132712), we get a palindrome (43855834).

The spelling of 21723122 in words is "twenty-one million, seven hundred twenty-three thousand, one hundred twenty-two".