166521265 has 24 divisors (see below), whose sum is σ = 210746088. Its totient is φ = 126297600.

The previous prime is 166521247. The next prime is 166521293. The reversal of 166521265 is 562125661.

It can be written as a sum of positive squares in 4 ways, for example, as 46662561 + 119858704 = 6831^2 + 10948^2 .

It is a de Polignac number, because none of the positive numbers 2^k-166521265 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166521265.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 415065 + ... + 415465.

It is an arithmetic number, because the mean of its divisors is an integer number (8781087).

Almost surely, 2^166521265 is an apocalyptic number.

It is an amenable number.

166521265 is a deficient number, since it is larger than the sum of its proper divisors (44224823).

166521265 is a wasteful number, since it uses less digits than its factorization.

166521265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609 (or 586 counting only the distinct ones).

The product of its digits is 21600, while the sum is 34.

The square root of 166521265 is about 12904.3118762683. The cubic root of 166521265 is about 550.1611263460.

The spelling of 166521265 in words is "one hundred sixty-six million, five hundred twenty-one thousand, two hundred sixty-five".