20997597 has 24 divisors (see below), whose sum is σ = 29782368. Its totient is φ = 13156000.

The previous prime is 20997583. The next prime is 20997619. The reversal of 20997597 is 79579902.

It is a de Polignac number, because none of the positive numbers 2^k-20997597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20997517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 160222 + ... + 160352.

It is an arithmetic number, because the mean of its divisors is an integer number (1240932).

Almost surely, 2^20997597 is an apocalyptic number.

It is an amenable number.

20997597 is a deficient number, since it is larger than the sum of its proper divisors (8784771).

20997597 is a wasteful number, since it uses less digits than its factorization.

20997597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 357210, while the sum is 48.

The square root of 20997597 is about 4582.3134986598. The cubic root of 20997597 is about 275.8818939116.

The spelling of 20997597 in words is "twenty million, nine hundred ninety-seven thousand, five hundred ninety-seven".