20896915691 has 4 divisors (see below), whose sum is σ = 20927512152. Its totient is φ = 20866319232.

The previous prime is 20896915667. The next prime is 20896915709. The reversal of 20896915691 is 19651969802.

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

It is a cyclic number.

It is not a de Polignac number, because 20896915691 - 2²⁶ = 20829806827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20896911691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15297206 + ... + 15298571.

It is an arithmetic number, because the mean of its divisors is an integer number (5231878038).

Almost surely, 2^20896915691 is an apocalyptic number.

20896915691 is a deficient number, since it is larger than the sum of its proper divisors (30596461).

20896915691 is an equidigital number, since it uses as much as digits as its factorization.

20896915691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30596460.

The product of its (nonzero) digits is 2099520, while the sum is 56.

The spelling of 20896915691 in words is "twenty billion, eight hundred ninety-six million, nine hundred fifteen thousand, six hundred ninety-one".