165819947 has 2 divisors, whose sum is σ = 165819948. Its totient is φ = 165819946.

The previous prime is 165819943. The next prime is 165819959. The reversal of 165819947 is 749918561.

165819947 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165819947 - 2² = 165819943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 165819895 and 165819904.

It is not a weakly prime, because it can be changed into another prime (165819943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82909973 + 82909974.

It is an arithmetic number, because the mean of its divisors is an integer number (82909974).

Almost surely, 2^165819947 is an apocalyptic number.

165819947 is a deficient number, since it is larger than the sum of its proper divisors (1).

165819947 is an equidigital number, since it uses as much as digits as its factorization.

165819947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 50.

The square root of 165819947 is about 12877.1094194311. The cubic root of 165819947 is about 549.3876899235.

The spelling of 165819947 in words is "one hundred sixty-five million, eight hundred nineteen thousand, nine hundred forty-seven".