161632121400 has 288 divisors, whose sum is σ = 564064849920. Its totient is φ = 41433120000.

The previous prime is 161632121389. The next prime is 161632121401. The reversal of 161632121400 is 4121236161.

It is a happy number.

161632121400 is a `hidden beast` number, since 1 + 6 + 1 + 632 + 1 + 21 + 4 + 0 + 0 = 666.

It is a super-2 number, since 2×161632121400² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161632121401) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8416209 + ... + 8435391.

Almost surely, 2^161632121400 is an apocalyptic number.

161632121400 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 161632121400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282032424960).

161632121400 is an abundant number, since it is smaller than the sum of its proper divisors (402432728520).

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

161632121400 is a wasteful number, since it uses less digits than its factorization.

161632121400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19387 (or 19375 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

Adding to 161632121400 its reverse (4121236161), we get a palindrome (165753357561).

The spelling of 161632121400 in words is "one hundred sixty-one billion, six hundred thirty-two million, one hundred twenty-one thousand, four hundred".