161869490 has 16 divisors (see below), whose sum is σ = 291933720. Its totient is φ = 64621440.

The previous prime is 161869489. The next prime is 161869541. The reversal of 161869490 is 94968161.

It can be written as a sum of positive squares in 4 ways, for example, as 119006281 + 42863209 = 10909^2 + 6547^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10325 + ... + 20744.

Almost surely, 2^161869490 is an apocalyptic number.

161869490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161869490 is a deficient number, since it is larger than the sum of its proper divisors (130064230).

161869490 is a wasteful number, since it uses less digits than its factorization.

161869490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31597.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 161869490 is about 12722.7941113578. The cubic root of 161869490 is about 544.9897481448.

The spelling of 161869490 in words is "one hundred sixty-one million, eight hundred sixty-nine thousand, four hundred ninety".