2157184391 has 2 divisors, whose sum is σ = 2157184392. Its totient is φ = 2157184390.

The previous prime is 2157184363. The next prime is 2157184423. The reversal of 2157184391 is 1934817512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2157184391 - 2¹⁰ = 2157183367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157184331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078592195 + 1078592196.

It is an arithmetic number, because the mean of its divisors is an integer number (1078592196).

Almost surely, 2^2157184391 is an apocalyptic number.

2157184391 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157184391 is an equidigital number, since it uses as much as digits as its factorization.

2157184391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 41.

The square root of 2157184391 is about 46445.4991468495. The cubic root of 2157184391 is about 1292.0988988935.

The spelling of 2157184391 in words is "two billion, one hundred fifty-seven million, one hundred eighty-four thousand, three hundred ninety-one".