161255991552 has 72 divisors (see below), whose sum is σ = 430226270880. Its totient is φ = 53620469760.

The previous prime is 161255991551. The next prime is 161255991599. The reversal of 161255991552 is 255199552161.

It is a super-2 number, since 2×161255991552² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161255991495 and 161255991504.

It is not an unprimeable number, because it can be changed into a prime (161255991551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57427 + ... + 570797.

Almost surely, 2^161255991552 is an apocalyptic number.

161255991552 is a gapful number since it is divisible by the number (12) 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 161255991552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215113135440).

161255991552 is an abundant number, since it is smaller than the sum of its proper divisors (268970279328).

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

161255991552 is an equidigital number, since it uses as much as digits as its factorization.

161255991552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513799 (or 513785 counting only the distinct ones).

The product of its digits is 1215000, while the sum is 51.

The spelling of 161255991552 in words is "one hundred sixty-one billion, two hundred fifty-five million, nine hundred ninety-one thousand, five hundred fifty-two".