21660922 has 4 divisors (see below), whose sum is σ = 32491386. Its totient is φ = 10830460.

The previous prime is 21660901. The next prime is 21660923. The reversal of 21660922 is 22906612.

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

It can be written as a sum of positive squares in only one way, i.e., 18740241 + 2920681 = 4329^2 + 1709^2 .

It is not an unprimeable number, because it can be changed into a prime (21660923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5415229 + ... + 5415232.

Almost surely, 2^21660922 is an apocalyptic number.

21660922 is a deficient number, since it is larger than the sum of its proper divisors (10830464).

21660922 is a wasteful number, since it uses less digits than its factorization.

21660922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10830463.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21660922 is about 4654.1295641613. The cubic root of 21660922 is about 278.7569128304.

The spelling of 21660922 in words is "twenty-one million, six hundred sixty thousand, nine hundred twenty-two".