20194168691 has 4 divisors (see below), whose sum is σ = 20739957072. Its totient is φ = 19648380312.

The previous prime is 20194168679. The next prime is 20194168739. The reversal of 20194168691 is 19686149102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19686149102 = 2 ⋅9843074551.

It is a cyclic number.

It is not a de Polignac number, because 20194168691 - 2⁶ = 20194168627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20194167691) 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, 272894135 + ... + 272894208.

It is an arithmetic number, because the mean of its divisors is an integer number (5184989268).

Almost surely, 2^20194168691 is an apocalyptic number.

20194168691 is a deficient number, since it is larger than the sum of its proper divisors (545788381).

20194168691 is an equidigital number, since it uses as much as digits as its factorization.

20194168691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545788380.

The product of its (nonzero) digits is 186624, while the sum is 47.

The spelling of 20194168691 in words is "twenty billion, one hundred ninety-four million, one hundred sixty-eight thousand, six hundred ninety-one".