221017308 has 12 divisors (see below), whose sum is σ = 515707080. Its totient is φ = 73672432.

The previous prime is 221017301. The next prime is 221017331. The reversal of 221017308 is 803710122.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221017301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9209043 + ... + 9209066.

It is an arithmetic number, because the mean of its divisors is an integer number (42975590).

Almost surely, 2^221017308 is an apocalyptic number.

It is an amenable number.

221017308 is an abundant number, since it is smaller than the sum of its proper divisors (294689772).

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

221017308 is a wasteful number, since it uses less digits than its factorization.

221017308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18418116 (or 18418114 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 221017308 is about 14866.6508669572. The cubic root of 221017308 is about 604.6101424761.

The spelling of 221017308 in words is "two hundred twenty-one million, seventeen thousand, three hundred eight".