165042491 has 2 divisors, whose sum is σ = 165042492. Its totient is φ = 165042490.

The previous prime is 165042439. The next prime is 165042499. The reversal of 165042491 is 194240561.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165042491 is a prime.

It is not a weakly prime, because it can be changed into another prime (165042499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82521245 + 82521246.

It is an arithmetic number, because the mean of its divisors is an integer number (82521246).

Almost surely, 2^165042491 is an apocalyptic number.

165042491 is a deficient number, since it is larger than the sum of its proper divisors (1).

165042491 is an equidigital number, since it uses as much as digits as its factorization.

165042491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 165042491 is about 12846.8864321282. The cubic root of 165042491 is about 548.5277330034.

The spelling of 165042491 in words is "one hundred sixty-five million, forty-two thousand, four hundred ninety-one".