181881840 has 80 divisors (see below), whose sum is σ = 644387328. Its totient is φ = 41572608.

The previous prime is 181881839. The next prime is 181881853. The reversal of 181881840 is 48188181.

181881840 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52452 + ... + 55811.

Almost surely, 2^181881840 is an apocalyptic number.

181881840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181881840 is an abundant number, since it is smaller than the sum of its proper divisors (462505488).

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

181881840 is a wasteful number, since it uses less digits than its factorization.

181881840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108286 (or 108280 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 39.

The square root of 181881840 is about 13486.3575512441. The cubic root of 181881840 is about 566.5824434611.

The spelling of 181881840 in words is "one hundred eighty-one million, eight hundred eighty-one thousand, eight hundred forty".