181521667140 has 96 divisors (see below), whose sum is σ = 562061759616. Its totient is φ = 43402429440.

The previous prime is 181521667109. The next prime is 181521667141. The reversal of 181521667140 is 41766125181.

It is a junction number, because it is equal to n+sod(n) for n = 181521667092 and 181521667101.

It is not an unprimeable number, because it can be changed into a prime (181521667141) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1835607 + ... + 1931966.

It is an arithmetic number, because the mean of its divisors is an integer number (5854809996).

Almost surely, 2^181521667140 is an apocalyptic number.

181521667140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181521667140 is an abundant number, since it is smaller than the sum of its proper divisors (380540092476).

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

181521667140 is a wasteful number, since it uses less digits than its factorization.

181521667140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3767669 (or 3767667 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 42.

The spelling of 181521667140 in words is "one hundred eighty-one billion, five hundred twenty-one million, six hundred sixty-seven thousand, one hundred forty".