221660540 has 24 divisors (see below), whose sum is σ = 480504192. Its totient is φ = 85803840.

The previous prime is 221660539. The next prime is 221660557. The reversal of 221660540 is 45066122.

221660540 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178139 + ... + 179378.

It is an arithmetic number, because the mean of its divisors is an integer number (20021008).

Almost surely, 2^221660540 is an apocalyptic number.

221660540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221660540 is an abundant number, since it is smaller than the sum of its proper divisors (258843652).

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

221660540 is a wasteful number, since it uses less digits than its factorization.

221660540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357557 (or 357555 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 221660540 is about 14888.2685359984. The cubic root of 221660540 is about 605.1961115480.

The spelling of 221660540 in words is "two hundred twenty-one million, six hundred sixty thousand, five hundred forty".