20900197 has 4 divisors (see below), whose sum is σ = 20926476. Its totient is φ = 20873920.

The previous prime is 20900189. The next prime is 20900221. The reversal of 20900197 is 79100902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2461761 + 18438436 = 1569^2 + 4294^2 .

It is a cyclic number.

It is not a de Polignac number, because 20900197 - 2³ = 20900189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20900177) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11908 + ... + 13549.

It is an arithmetic number, because the mean of its divisors is an integer number (5231619).

Almost surely, 2^20900197 is an apocalyptic number.

It is an amenable number.

20900197 is a deficient number, since it is larger than the sum of its proper divisors (26279).

20900197 is an equidigital number, since it uses as much as digits as its factorization.

20900197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26278.

The product of its (nonzero) digits is 1134, while the sum is 28.

The square root of 20900197 is about 4571.6733260372. The cubic root of 20900197 is about 275.4546616608.

The spelling of 20900197 in words is "twenty million, nine hundred thousand, one hundred ninety-seven".