21185080191 has 12 divisors (see below), whose sum is σ = 33382550760. Its totient is φ = 12839442480.

The previous prime is 21185080187. The next prime is 21185080243. The reversal of 21185080191 is 19108058112.

It is not a de Polignac number, because 21185080191 - 2² = 21185080187 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21185080291) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 106995256 + ... + 106995453.

It is an arithmetic number, because the mean of its divisors is an integer number (2781879230).

Almost surely, 2^21185080191 is an apocalyptic number.

21185080191 is a deficient number, since it is larger than the sum of its proper divisors (12197470569).

21185080191 is a wasteful number, since it uses less digits than its factorization.

21185080191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213990726 (or 213990723 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 36.

The spelling of 21185080191 in words is "twenty-one billion, one hundred eighty-five million, eighty thousand, one hundred ninety-one".