161669691 has 24 divisors (see below), whose sum is σ = 244352160. Its totient is φ = 102807936.

The previous prime is 161669671. The next prime is 161669699. The reversal of 161669691 is 196966161.

161669691 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 161669691 - 2¹⁰ = 161668667 is a prime.

It is a super-2 number, since 2×161669691² = 52274177976070962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161669699) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 93745 + ... + 95453.

It is an arithmetic number, because the mean of its divisors is an integer number (10181340).

Almost surely, 2^161669691 is an apocalyptic number.

161669691 is a deficient number, since it is larger than the sum of its proper divisors (82682469).

161669691 is a wasteful number, since it uses less digits than its factorization.

161669691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2195 (or 2192 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 161669691 is about 12714.9396774031. The cubic root of 161669691 is about 544.7654249601.

The spelling of 161669691 in words is "one hundred sixty-one million, six hundred sixty-nine thousand, six hundred ninety-one".