161209557600 has 1152 divisors, whose sum is σ = 685396131840. Its totient is φ = 31982100480.

The previous prime is 161209557571. The next prime is 161209557617. The reversal of 161209557600 is 6755902161.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 336554161 + ... + 336554639.

It is an arithmetic number, because the mean of its divisors is an integer number (594961920).

Almost surely, 2^161209557600 is an apocalyptic number.

161209557600 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 161209557600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342698065920).

161209557600 is an abundant number, since it is smaller than the sum of its proper divisors (524186574240).

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

161209557600 is a wasteful number, since it uses less digits than its factorization.

161209557600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612 (or 599 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 42.

The spelling of 161209557600 in words is "one hundred sixty-one billion, two hundred nine million, five hundred fifty-seven thousand, six hundred".