20195214091 has 4 divisors (see below), whose sum is σ = 21748692112. Its totient is φ = 18641736072.

The previous prime is 20195214043. The next prime is 20195214121. The reversal of 20195214091 is 19041259102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19041259102 = 2 ⋅9520629551.

It is a cyclic number.

It is not a de Polignac number, because 20195214091 - 2⁹ = 20195213579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20195214031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 776738991 + ... + 776739016.

It is an arithmetic number, because the mean of its divisors is an integer number (5437173028).

Almost surely, 2^20195214091 is an apocalyptic number.

20195214091 is a deficient number, since it is larger than the sum of its proper divisors (1553478021).

20195214091 is a wasteful number, since it uses less digits than its factorization.

20195214091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1553478020.

The product of its (nonzero) digits is 6480, while the sum is 34.

The spelling of 20195214091 in words is "twenty billion, one hundred ninety-five million, two hundred fourteen thousand, ninety-one".