165576421 has 2 divisors, whose sum is σ = 165576422. Its totient is φ = 165576420.

The previous prime is 165576407. The next prime is 165576427. The reversal of 165576421 is 124675561.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150945796 + 14630625 = 12286^2 + 3825^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165576421 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165576427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82788210 + 82788211.

It is an arithmetic number, because the mean of its divisors is an integer number (82788211).

Almost surely, 2^165576421 is an apocalyptic number.

It is an amenable number.

165576421 is a deficient number, since it is larger than the sum of its proper divisors (1).

165576421 is an equidigital number, since it uses as much as digits as its factorization.

165576421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50400, while the sum is 37.

The square root of 165576421 is about 12867.6501739828. The cubic root of 165576421 is about 549.1186114481.

The spelling of 165576421 in words is "one hundred sixty-five million, five hundred seventy-six thousand, four hundred twenty-one".