161801077320 has 96 divisors (see below), whose sum is σ = 526631035320. Its totient is φ = 43083156480.

The previous prime is 161801077309. The next prime is 161801077331. The reversal of 161801077320 is 23770108161.

161801077320 is a `hidden beast` number, since 1 + 618 + 0 + 1 + 0 + 7 + 7 + 32 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (161801077309) and next prime (161801077331).

It can be written as a sum of positive squares in 4 ways, for example, as 158259161124 + 3541916196 = 397818^2 + 59514^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88221 + ... + 575660.

Almost surely, 2^161801077320 is an apocalyptic number.

161801077320 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 161801077320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263315517660).

161801077320 is an abundant number, since it is smaller than the sum of its proper divisors (364829958000).

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

161801077320 is a wasteful number, since it uses less digits than its factorization.

161801077320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664575 (or 664568 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The spelling of 161801077320 in words is "one hundred sixty-one billion, eight hundred one million, seventy-seven thousand, three hundred twenty".