21023722 has 8 divisors (see below), whose sum is σ = 32130756. Its totient is φ = 10313472.

The previous prime is 21023701. The next prime is 21023731. The reversal of 21023722 is 22732012.

It can be written as a sum of positive squares in 2 ways, for example, as 20602521 + 421201 = 4539^2 + 649^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21023722.

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, 99063 + ... + 99274.

Almost surely, 2^21023722 is an apocalyptic number.

21023722 is a deficient number, since it is larger than the sum of its proper divisors (11107034).

21023722 is a wasteful number, since it uses less digits than its factorization.

21023722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198392.

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

The square root of 21023722 is about 4585.1632468212. The cubic root of 21023722 is about 275.9962629894.

Adding to 21023722 its reverse (22732012), we get a palindrome (43755734).

It can be divided in two parts, 210 and 23722, that added together give a palindrome (23932).

The spelling of 21023722 in words is "twenty-one million, twenty-three thousand, seven hundred twenty-two".