181561413600 has 1152 divisors, whose sum is σ = 793749196800. Its totient is φ = 39171686400.

The previous prime is 181561413581. The next prime is 181561413611. The reversal of 181561413600 is 6314165181.

It is a happy number.

181561413600 is a `hidden beast` number, since 1 + 8 + 1 + 5 + 6 + 1 + 41 + 3 + 600 = 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 191 ways as a sum of consecutive naturals, for example, 206085160 + ... + 206086040.

It is an arithmetic number, because the mean of its divisors is an integer number (689018400).

Almost surely, 2^181561413600 is an apocalyptic number.

181561413600 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 181561413600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (396874598400).

181561413600 is an abundant number, since it is smaller than the sum of its proper divisors (612187783200).

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

181561413600 is a wasteful number, since it uses less digits than its factorization.

181561413600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 993 (or 974 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

Adding to 181561413600 its reverse (6314165181), we get a palindrome (187875578781).

The spelling of 181561413600 in words is "one hundred eighty-one billion, five hundred sixty-one million, four hundred thirteen thousand, six hundred".