21966634 has 4 divisors (see below), whose sum is σ = 32949954. Its totient is φ = 10983316.

The previous prime is 21966629. The next prime is 21966643. The reversal of 21966634 is 43666912.

It is a happy number.

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., 18533025 + 3433609 = 4305^2 + 1853^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21966593 and 21966602.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5491657 + ... + 5491660.

Almost surely, 2^21966634 is an apocalyptic number.

21966634 is a deficient number, since it is larger than the sum of its proper divisors (10983320).

21966634 is a wasteful number, since it uses less digits than its factorization.

21966634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10983319.

The product of its digits is 46656, while the sum is 37.

The square root of 21966634 is about 4686.8575826453. The cubic root of 21966634 is about 280.0622055670.

The spelling of 21966634 in words is "twenty-one million, nine hundred sixty-six thousand, six hundred thirty-four".