221636940 has 96 divisors (see below), whose sum is σ = 711298560. Its totient is φ = 50512896.

The previous prime is 221636929. The next prime is 221636941. The reversal of 221636940 is 49636122.

It is not an unprimeable number, because it can be changed into a prime (221636941) 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, 219156 + ... + 220164.

It is an arithmetic number, because the mean of its divisors is an integer number (7409360).

Almost surely, 2^221636940 is an apocalyptic number.

221636940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221636940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (355649280).

221636940 is an abundant number, since it is smaller than the sum of its proper divisors (489661620).

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

221636940 is a wasteful number, since it uses less digits than its factorization.

221636940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1551 (or 1549 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 221636940 is about 14887.4759445649. The cubic root of 221636940 is about 605.1746325556.

The spelling of 221636940 in words is "two hundred twenty-one million, six hundred thirty-six thousand, nine hundred forty".