180721940 has 48 divisors (see below), whose sum is σ = 447734784. Its totient is φ = 59961600.

The previous prime is 180721927. The next prime is 180721993. The reversal of 180721940 is 49127081.

It is a junction number, because it is equal to n+sod(n) for n = 180721897 and 180721906.

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, 16481 + ... + 25160.

It is an arithmetic number, because the mean of its divisors is an integer number (9327808).

Almost surely, 2^180721940 is an apocalyptic number.

180721940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

180721940 is an abundant number, since it is smaller than the sum of its proper divisors (267012844).

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

180721940 is a wasteful number, since it uses less digits than its factorization.

180721940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41688 (or 41686 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 180721940 is about 13443.2860566158. The cubic root of 180721940 is about 565.3754676616.

The spelling of 180721940 in words is "one hundred eighty million, seven hundred twenty-one thousand, nine hundred forty".