161252451220 has 96 divisors (see below), whose sum is σ = 404062944768. Its totient is φ = 52852580352.

The previous prime is 161252451169. The next prime is 161252451221. The reversal of 161252451220 is 22154252161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161252451221) 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 31 ways as a sum of consecutive naturals, for example, 6017692 + ... + 6044428.

It is an arithmetic number, because the mean of its divisors is an integer number (4208989008).

Almost surely, 2^161252451220 is an apocalyptic number.

161252451220 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 161252451220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (202031472384).

161252451220 is an abundant number, since it is smaller than the sum of its proper divisors (242810493548).

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

161252451220 is a wasteful number, since it uses less digits than its factorization.

161252451220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28649 (or 28647 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 31.

The spelling of 161252451220 in words is "one hundred sixty-one billion, two hundred fifty-two million, four hundred fifty-one thousand, two hundred twenty".