221893940 has 24 divisors (see below), whose sum is σ = 466258632. Its totient is φ = 88704000.

The previous prime is 221893937. The next prime is 221893967. The reversal of 221893940 is 49398122.

It can be written as a sum of positive squares in 4 ways, for example, as 2202256 + 219691684 = 1484^2 + 14822^2 .

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 221893894 and 221893903.

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, 58172 + ... + 61868.

It is an arithmetic number, because the mean of its divisors is an integer number (19427443).

Almost surely, 2^221893940 is an apocalyptic number.

221893940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221893940 is an abundant number, since it is smaller than the sum of its proper divisors (244364692).

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

221893940 is a wasteful number, since it uses less digits than its factorization.

221893940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6707 (or 6705 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 221893940 is about 14896.1048599961. The cubic root of 221893940 is about 605.4084530913.

The spelling of 221893940 in words is "two hundred twenty-one million, eight hundred ninety-three thousand, nine hundred forty".