16165921 has 2 divisors, whose sum is σ = 16165922. Its totient is φ = 16165920.

The previous prime is 16165907. The next prime is 16165937. The reversal of 16165921 is 12956161.

16165921 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 can be written as a sum of positive squares in only one way, i.e., 8767521 + 7398400 = 2961^2 + 2720^2 .

It is a cyclic number.

It is not a de Polignac number, because 16165921 - 2⁵ = 16165889 is a prime.

It is a super-2 number, since 2×16165921² = 522674003556482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16165991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8082960 + 8082961.

It is an arithmetic number, because the mean of its divisors is an integer number (8082961).

Almost surely, 2^16165921 is an apocalyptic number.

It is an amenable number.

16165921 is a deficient number, since it is larger than the sum of its proper divisors (1).

16165921 is an equidigital number, since it uses as much as digits as its factorization.

16165921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 31.

The square root of 16165921 is about 4020.6866329024. The cubic root of 16165921 is about 252.8522469941.

The spelling of 16165921 in words is "sixteen million, one hundred sixty-five thousand, nine hundred twenty-one".