161261755200 has 2688 divisors, whose sum is σ = 812747980800. Its totient is φ = 30098718720.

The previous prime is 161261755169. The next prime is 161261755243. The reversal of 161261755200 is 2557162161.

161261755200 is a `hidden beast` number, since 1 + 6 + 1 + 2 + 61 + 75 + 520 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 1269777537 + ... + 1269777663.

It is an arithmetic number, because the mean of its divisors is an integer number (302361600).

Almost surely, 2^161261755200 is an apocalyptic number.

161261755200 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 161261755200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (406373990400).

161261755200 is an abundant number, since it is smaller than the sum of its proper divisors (651486225600).

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

161261755200 is a wasteful number, since it uses less digits than its factorization.

161261755200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The spelling of 161261755200 in words is "one hundred sixty-one billion, two hundred sixty-one million, seven hundred fifty-five thousand, two hundred".