161591430 has 128 divisors (see below), whose sum is σ = 520805376. Its totient is φ = 30988800.

The previous prime is 161591407. The next prime is 161591431. The reversal of 161591430 is 34195161.

It is a super-2 number, since 2×161591430² = 52223580498889800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161591431) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 27340 + ... + 32720.

It is an arithmetic number, because the mean of its divisors is an integer number (4068792).

Almost surely, 2^161591430 is an apocalyptic number.

161591430 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161591430, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260402688).

161591430 is an abundant number, since it is smaller than the sum of its proper divisors (359213946).

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

161591430 is a wasteful number, since it uses less digits than its factorization.

161591430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5422.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 161591430 is about 12711.8617833896. The cubic root of 161591430 is about 544.6775074951.

The spelling of 161591430 in words is "one hundred sixty-one million, five hundred ninety-one thousand, four hundred thirty".