161691264 has 96 divisors (see below), whose sum is σ = 531779040. Its totient is φ = 46195200.

The previous prime is 161691251. The next prime is 161691307. The reversal of 161691264 is 462196161.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×161691264² = 52288129707835392, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1962 + ... + 18089.

It is an arithmetic number, because the mean of its divisors is an integer number (5539365).

Almost surely, 2^161691264 is an apocalyptic number.

161691264 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161691264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265889520).

161691264 is an abundant number, since it is smaller than the sum of its proper divisors (370087776).

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

161691264 is a wasteful number, since it uses less digits than its factorization.

161691264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20078 (or 20063 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 161691264 is about 12715.7879818751. The cubic root of 161691264 is about 544.7896548198.

The spelling of 161691264 in words is "one hundred sixty-one million, six hundred ninety-one thousand, two hundred sixty-four".