221256213 has 16 divisors (see below), whose sum is σ = 308641536. Its totient is φ = 140840960.

The previous prime is 221256193. The next prime is 221256221. The reversal of 221256213 is 312652122.

It is a cyclic number.

It is not a de Polignac number, because 221256213 - 2⁵ = 221256181 is a prime.

It is a super-2 number, since 2×221256213² = 97908623582202738, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221256293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13356 + ... + 24917.

It is an arithmetic number, because the mean of its divisors is an integer number (19290096).

Almost surely, 2^221256213 is an apocalyptic number.

It is an amenable number.

221256213 is a deficient number, since it is larger than the sum of its proper divisors (87385323).

221256213 is a wasteful number, since it uses less digits than its factorization.

221256213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38364.

The product of its digits is 1440, while the sum is 24.

The square root of 221256213 is about 14874.6836268877. The cubic root of 221256213 is about 604.8279118048.

The spelling of 221256213 in words is "two hundred twenty-one million, two hundred fifty-six thousand, two hundred thirteen".