20397091 has 12 divisors (see below), whose sum is σ = 24146416. Its totient is φ = 17115120.

The previous prime is 20397079. The next prime is 20397137. The reversal of 20397091 is 19079302.

It is not a de Polignac number, because 20397091 - 2⁷ = 20396963 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20397031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4911 + ... + 8056.

Almost surely, 2^20397091 is an apocalyptic number.

20397091 is a deficient number, since it is larger than the sum of its proper divisors (3749325).

20397091 is a wasteful number, since it uses less digits than its factorization.

20397091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13002 (or 12991 counting only the distinct ones).

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 20397091 is about 4516.3138730606. The cubic root of 20397091 is about 273.2264531892.

The spelling of 20397091 in words is "twenty million, three hundred ninety-seven thousand, ninety-one".