165631523 has 2 divisors, whose sum is σ = 165631524. Its totient is φ = 165631522.

The previous prime is 165631517. The next prime is 165631537. The reversal of 165631523 is 325136561.

It is a weak prime.

It is an emirp because it is prime and its reverse (325136561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165631523 - 2⁴ = 165631507 is a prime.

It is a super-2 number, since 2×165631523² = 54867602822599058, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165631523.

It is not a weakly prime, because it can be changed into another prime (165631723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82815761 + 82815762.

It is an arithmetic number, because the mean of its divisors is an integer number (82815762).

Almost surely, 2^165631523 is an apocalyptic number.

165631523 is a deficient number, since it is larger than the sum of its proper divisors (1).

165631523 is an equidigital number, since it uses as much as digits as its factorization.

165631523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16200, while the sum is 32.

The square root of 165631523 is about 12869.7911016457. The cubic root of 165631523 is about 549.1795182240.

The spelling of 165631523 in words is "one hundred sixty-five million, six hundred thirty-one thousand, five hundred twenty-three".