20997562 has 4 divisors (see below), whose sum is σ = 31496346. Its totient is φ = 10498780.

The previous prime is 20997553. The next prime is 20997583. The reversal of 20997562 is 26579902.

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., 20875761 + 121801 = 4569^2 + 349^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5249389 + ... + 5249392.

Almost surely, 2^20997562 is an apocalyptic number.

20997562 is a deficient number, since it is larger than the sum of its proper divisors (10498784).

20997562 is a wasteful number, since it uses less digits than its factorization.

20997562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10498783.

The product of its (nonzero) digits is 68040, while the sum is 40.

The square root of 20997562 is about 4582.3096796266. The cubic root of 20997562 is about 275.8817406263.

The spelling of 20997562 in words is "twenty million, nine hundred ninety-seven thousand, five hundred sixty-two".