11891929897 has 4 divisors (see below), whose sum is σ = 12069421456. Its totient is φ = 11714438340.

The previous prime is 11891929891. The next prime is 11891929939. The reversal of 11891929897 is 79892919811.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11891929897 - 2¹¹ = 11891927849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11891929891) 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, 88745679 + ... + 88745812.

It is an arithmetic number, because the mean of its divisors is an integer number (3017355364).

Almost surely, 2^11891929897 is an apocalyptic number.

It is an amenable number.

11891929897 is a deficient number, since it is larger than the sum of its proper divisors (177491559).

11891929897 is an equidigital number, since it uses as much as digits as its factorization.

11891929897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177491558.

The product of its digits is 5878656, while the sum is 64.

The spelling of 11891929897 in words is "eleven billion, eight hundred ninety-one million, nine hundred twenty-nine thousand, eight hundred ninety-seven".