21315922 has 8 divisors (see below), whose sum is σ = 32838156. Its totient is φ = 10369872.

The previous prime is 21315919. The next prime is 21315923. The reversal of 21315922 is 22951312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20784481 + 531441 = 4559^2 + 729^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21315923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143953 + ... + 144100.

Almost surely, 2^21315922 is an apocalyptic number.

21315922 is a deficient number, since it is larger than the sum of its proper divisors (11522234).

21315922 is a wasteful number, since it uses less digits than its factorization.

21315922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288092.

The product of its digits is 1080, while the sum is 25.

The square root of 21315922 is about 4616.9169366581. The cubic root of 21315922 is about 277.2690370524.

The spelling of 21315922 in words is "twenty-one million, three hundred fifteen thousand, nine hundred twenty-two".