21966436 has 6 divisors (see below), whose sum is σ = 38441270. Its totient is φ = 10983216.

The previous prime is 21966401. The next prime is 21966463. The reversal of 21966436 is 63466912.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20160100 + 1806336 = 4490^2 + 1344^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21966395 and 21966404.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2745801 + ... + 2745808.

Almost surely, 2^21966436 is an apocalyptic number.

It is an amenable number.

21966436 is a deficient number, since it is larger than the sum of its proper divisors (16474834).

21966436 is a wasteful number, since it uses less digits than its factorization.

21966436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5491613 (or 5491611 counting only the distinct ones).

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

The square root of 21966436 is about 4686.8364597029. The cubic root of 21966436 is about 280.0613641016.

The spelling of 21966436 in words is "twenty-one million, nine hundred sixty-six thousand, four hundred thirty-six".