161331100 has 72 divisors (see below), whose sum is σ = 410980640. Its totient is φ = 53809920.

The previous prime is 161331097. The next prime is 161331103. The reversal of 161331100 is 1133161.

It is an interprime number because it is at equal distance from previous prime (161331097) and next prime (161331103).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161331103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22786 + ... + 29014.

Almost surely, 2^161331100 is an apocalyptic number.

161331100 is a gapful number since it is divisible by the number (10) 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 161331100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (205490320).

161331100 is an abundant number, since it is smaller than the sum of its proper divisors (249649540).

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

161331100 is a wasteful number, since it uses less digits than its factorization.

161331100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6287 (or 6280 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 161331100 is about 12701.6180071674. The cubic root of 161331100 is about 544.3848514841.

Adding to 161331100 its reverse (1133161), we get a palindrome (162464261).

The spelling of 161331100 in words is "one hundred sixty-one million, three hundred thirty-one thousand, one hundred".