845571120091 has 4 divisors (see below), whose sum is σ = 845572963752. Its totient is φ = 845569276432.

The previous prime is 845571120083. The next prime is 845571120113. The reversal of 845571120091 is 190021175548.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 845571120091 - 2³ = 845571120083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (845571120001) 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, 363711 + ... + 1350343.

It is an arithmetic number, because the mean of its divisors is an integer number (211393240938).

Almost surely, 2^845571120091 is an apocalyptic number.

845571120091 is a deficient number, since it is larger than the sum of its proper divisors (1843661).

845571120091 is an equidigital number, since it uses as much as digits as its factorization.

845571120091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1843660.

The product of its (nonzero) digits is 100800, while the sum is 43.

The spelling of 845571120091 in words is "eight hundred forty-five billion, five hundred seventy-one million, one hundred twenty thousand, ninety-one".