20195091 has 24 divisors (see below), whose sum is σ = 33606144. Its totient is φ = 11447280.

The previous prime is 20195089. The next prime is 20195111. The reversal of 20195091 is 19059102.

It is a happy number.

It is not a de Polignac number, because 20195091 - 2¹ = 20195089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20195011) by changing a digit.

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 in 23 ways as a sum of consecutive naturals, for example, 7030 + ... + 9476.

It is an arithmetic number, because the mean of its divisors is an integer number (1400256).

Almost surely, 2^20195091 is an apocalyptic number.

20195091 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20195091 is a deficient number, since it is larger than the sum of its proper divisors (13411053).

20195091 is a wasteful number, since it uses less digits than its factorization.

20195091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2591 (or 2588 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 20195091 is about 4493.8948585831. The cubic root of 20195091 is about 272.3215047428.

The spelling of 20195091 in words is "twenty million, one hundred ninety-five thousand, ninety-one".