165646643 has 2 divisors, whose sum is σ = 165646644. Its totient is φ = 165646642.

The previous prime is 165646639. The next prime is 165646673. The reversal of 165646643 is 346646561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165646643 - 2² = 165646639 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165646643.

It is not a weakly prime, because it can be changed into another prime (165646603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82823321 + 82823322.

It is an arithmetic number, because the mean of its divisors is an integer number (82823322).

Almost surely, 2^165646643 is an apocalyptic number.

165646643 is a deficient number, since it is larger than the sum of its proper divisors (1).

165646643 is an equidigital number, since it uses as much as digits as its factorization.

165646643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311040, while the sum is 41.

The square root of 165646643 is about 12870.3785103625. The cubic root of 165646643 is about 549.1962286937.

The spelling of 165646643 in words is "one hundred sixty-five million, six hundred forty-six thousand, six hundred forty-three".