20797985 has 24 divisors (see below), whose sum is σ = 27370944. Its totient is φ = 15163200.

The previous prime is 20797981. The next prime is 20797999. The reversal of 20797985 is 58979702.

It is not a de Polignac number, because 20797985 - 2² = 20797981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20797981) 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, 127514 + ... + 127676.

It is an arithmetic number, because the mean of its divisors is an integer number (1140456).

Almost surely, 2^20797985 is an apocalyptic number.

It is an amenable number.

20797985 is a deficient number, since it is larger than the sum of its proper divisors (6572959).

20797985 is a wasteful number, since it uses less digits than its factorization.

20797985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 317520, while the sum is 47.

The square root of 20797985 is about 4560.4807860575. The cubic root of 20797985 is about 275.0048924749.

The spelling of 20797985 in words is "twenty million, seven hundred ninety-seven thousand, nine hundred eighty-five".