2181774905091 has 48 divisors (see below), whose sum is σ = 3271773974976. Its totient is φ = 1400226766848.

The previous prime is 2181774905041. The next prime is 2181774905113. The reversal of 2181774905091 is 1905094771812.

2181774905091 is a `hidden beast` number, since 2 + 1 + 8 + 17 + 7 + 490 + 50 + 91 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-2181774905091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2181774905041) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6558130 + ... + 6882776.

It is an arithmetic number, because the mean of its divisors is an integer number (68161957812).

Almost surely, 2^{2181774905091} is an apocalyptic number.

2181774905091 is a deficient number, since it is larger than the sum of its proper divisors (1089999069885).

2181774905091 is a wasteful number, since it uses less digits than its factorization.

2181774905091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324972 (or 324969 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 54.

The spelling of 2181774905091 in words is "two trillion, one hundred eighty-one billion, seven hundred seventy-four million, nine hundred five thousand, ninety-one".