161649775 has 18 divisors (see below), whose sum is σ = 233173320. Its totient is φ = 110844720.

The previous prime is 161649769. The next prime is 161649797. The reversal of 161649775 is 577946161.

161649775 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 161649775 - 2³ = 161649767 is a prime.

It is a super-2 number, since 2×161649775² = 52261299515101250, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 64755 + ... + 67204.

Almost surely, 2^161649775 is an apocalyptic number.

161649775 is a deficient number, since it is larger than the sum of its proper divisors (71523545).

161649775 is a wasteful number, since it uses less digits than its factorization.

161649775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131983 (or 131971 counting only the distinct ones).

The product of its digits is 317520, while the sum is 46.

The square root of 161649775 is about 12714.1564800816. The cubic root of 161649775 is about 544.7430542574.

The spelling of 161649775 in words is "one hundred sixty-one million, six hundred forty-nine thousand, seven hundred seventy-five".