20997572 has 12 divisors (see below), whose sum is σ = 36867600. Its totient is φ = 10463976.

The previous prime is 20997553. The next prime is 20997583. The reversal of 20997572 is 27579902.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7322 + ... + 9777.

It is an arithmetic number, because the mean of its divisors is an integer number (3072300).

Almost surely, 2^20997572 is an apocalyptic number.

It is an amenable number.

20997572 is a deficient number, since it is larger than the sum of its proper divisors (15870028).

20997572 is a wasteful number, since it uses less digits than its factorization.

20997572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17410 (or 17408 counting only the distinct ones).

The product of its (nonzero) digits is 79380, while the sum is 41.

The square root of 20997572 is about 4582.3107707793. The cubic root of 20997572 is about 275.8817844221.

The spelling of 20997572 in words is "twenty million, nine hundred ninety-seven thousand, five hundred seventy-two".