21951323 has 8 divisors (see below), whose sum is σ = 22699680. Its totient is φ = 21211200.

The previous prime is 21951263. The next prime is 21951329. The reversal of 21951323 is 32315912.

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

It is a cyclic number.

It is not a de Polignac number, because 21951323 - 2⁸ = 21951067 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21951292 and 21951301.

It is not an unprimeable number, because it can be changed into a prime (21951329) 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, 3623 + ... + 7551.

It is an arithmetic number, because the mean of its divisors is an integer number (2837460).

Almost surely, 2^21951323 is an apocalyptic number.

21951323 is a deficient number, since it is larger than the sum of its proper divisors (748357).

21951323 is a wasteful number, since it uses less digits than its factorization.

21951323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4117.

The product of its digits is 1620, while the sum is 26.

The square root of 21951323 is about 4685.2239007330. The cubic root of 21951323 is about 279.9971215690.

The spelling of 21951323 in words is "twenty-one million, nine hundred fifty-one thousand, three hundred twenty-three".