161959788 has 18 divisors (see below), whose sum is σ = 409398444. Its totient is φ = 53986584.

The previous prime is 161959769. The next prime is 161959793. The reversal of 161959788 is 887959161.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2249406 + ... + 2249477.

It is an arithmetic number, because the mean of its divisors is an integer number (22744358).

Almost surely, 2^161959788 is an apocalyptic number.

161959788 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

161959788 is an abundant number, since it is smaller than the sum of its proper divisors (247438656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161959788 is a wasteful number, since it uses less digits than its factorization.

161959788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4498893 (or 4498888 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 54.

The square root of 161959788 is about 12726.3422867688. The cubic root of 161959788 is about 545.0910691459.

The spelling of 161959788 in words is "one hundred sixty-one million, nine hundred fifty-nine thousand, seven hundred eighty-eight".