161987262720 has 288 divisors, whose sum is σ = 541990310400. Its totient is φ = 41176891392.

The previous prime is 161987262683. The next prime is 161987262737. The reversal of 161987262720 is 27262789161.

It is a happy number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 8788234 + ... + 8806646.

It is an arithmetic number, because the mean of its divisors is an integer number (1881910800).

Almost surely, 2^161987262720 is an apocalyptic number.

161987262720 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 161987262720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270995155200).

161987262720 is an abundant number, since it is smaller than the sum of its proper divisors (380003047680).

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

161987262720 is a wasteful number, since it uses less digits than its factorization.

161987262720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18545 (or 18531 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 51.

The spelling of 161987262720 in words is "one hundred sixty-one billion, nine hundred eighty-seven million, two hundred sixty-two thousand, seven hundred twenty".