165561669 has 48 divisors (see below), whose sum is σ = 303873024. Its totient is φ = 84499200.

The previous prime is 165561661. The next prime is 165561679. The reversal of 165561669 is 966165561.

165561669 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 165561669 - 2³ = 165561661 is a prime.

It is a super-2 number, since 2×165561669² = 54821332484131122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165561661) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22129 + ... + 28649.

It is an arithmetic number, because the mean of its divisors is an integer number (6330688).

Almost surely, 2^165561669 is an apocalyptic number.

It is an amenable number.

165561669 is a deficient number, since it is larger than the sum of its proper divisors (138311355).

165561669 is a wasteful number, since it uses less digits than its factorization.

165561669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6578 (or 6575 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 165561669 is about 12867.0769407818. The cubic root of 165561669 is about 549.1023030907.

It can be divided in two parts, 16556 and 1669, that added together give a square (18225 = 135²).

The spelling of 165561669 in words is "one hundred sixty-five million, five hundred sixty-one thousand, six hundred sixty-nine".