181537873920 has 1344 divisors, whose sum is σ = 745378792704. Its totient is φ = 42042654720.

The previous prime is 181537873901. The next prime is 181537873961. The reversal of 181537873920 is 29378735181.

It is a happy number.

181537873920 is a `hidden beast` number, since 1 + 8 + 1 + 537 + 87 + 3 + 9 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2976030690 + ... + 2976030750.

It is an arithmetic number, because the mean of its divisors is an integer number (554597316).

Almost surely, 2^181537873920 is an apocalyptic number.

181537873920 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 181537873920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (372689396352).

181537873920 is an abundant number, since it is smaller than the sum of its proper divisors (563840918784).

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

181537873920 is an equidigital number, since it uses as much as digits as its factorization.

181537873920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 54.

The spelling of 181537873920 in words is "one hundred eighty-one billion, five hundred thirty-seven million, eight hundred seventy-three thousand, nine hundred twenty".