221965408 has 24 divisors (see below), whose sum is σ = 499422672. Its totient is φ = 95127936.

The previous prime is 221965339. The next prime is 221965417. The reversal of 221965408 is 804569122.

221965408 is digitally balanced in base 2, 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 3 ways as a sum of consecutive naturals, for example, 495235 + ... + 495682.

It is an arithmetic number, because the mean of its divisors is an integer number (20809278).

Almost surely, 2^221965408 is an apocalyptic number.

221965408 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

221965408 is an abundant number, since it is smaller than the sum of its proper divisors (277457264).

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

221965408 is an equidigital number, since it uses as much as digits as its factorization.

221965408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990934 (or 990926 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 221965408 is about 14898.5035490146. The cubic root of 221965408 is about 605.4734431296.

The spelling of 221965408 in words is "two hundred twenty-one million, nine hundred sixty-five thousand, four hundred eight".