161118720 has 480 divisors, whose sum is σ = 679206528. Its totient is φ = 35831808.

The previous prime is 161118701. The next prime is 161118739. The reversal of 161118720 is 27811161.

It is an interprime number because it is at equal distance from previous prime (161118701) and next prime (161118739).

It is a tau number, because it is divible by the number of its divisors (480).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 47 ways as a sum of consecutive naturals, for example, 4354542 + ... + 4354578.

Almost surely, 2^161118720 is an apocalyptic number.

161118720 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 161118720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (339603264).

161118720 is an abundant number, since it is smaller than the sum of its proper divisors (518087808).

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

161118720 is an frugal number, since it uses more digits than its factorization.

161118720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 27.

The square root of 161118720 is about 12693.2549017185. The cubic root of 161118720 is about 544.1458663054.

Adding to 161118720 its reverse (27811161), we get a palindrome (188929881).

The spelling of 161118720 in words is "one hundred sixty-one million, one hundred eighteen thousand, seven hundred twenty".