2162181491 has 2 divisors, whose sum is σ = 2162181492. Its totient is φ = 2162181490.

The previous prime is 2162181473. The next prime is 2162181503. The reversal of 2162181491 is 1941812612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2162181491 - 2²⁶ = 2095072627 is a prime.

It is not a weakly prime, because it can be changed into another prime (2162181451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1081090745 + 1081090746.

It is an arithmetic number, because the mean of its divisors is an integer number (1081090746).

Almost surely, 2^2162181491 is an apocalyptic number.

2162181491 is a deficient number, since it is larger than the sum of its proper divisors (1).

2162181491 is an equidigital number, since it uses as much as digits as its factorization.

2162181491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 35.

The square root of 2162181491 is about 46499.2633382509. The cubic root of 2162181491 is about 1293.0958416635.

The spelling of 2162181491 in words is "two billion, one hundred sixty-two million, one hundred eighty-one thousand, four hundred ninety-one".