913231221 has 8 divisors (see below), whose sum is σ = 1391590464. Its totient is φ = 521846400.

The previous prime is 913231217. The next prime is 913231243. The reversal of 913231221 is 122132319.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 913231221 - 2² = 913231217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 913231191 and 913231200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (913231621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21743580 + ... + 21743621.

It is an arithmetic number, because the mean of its divisors is an integer number (173948808).

Almost surely, 2^913231221 is an apocalyptic number.

It is an amenable number.

913231221 is a deficient number, since it is larger than the sum of its proper divisors (478359243).

913231221 is a wasteful number, since it uses less digits than its factorization.

913231221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43487211.

The product of its digits is 648, while the sum is 24.

The square root of 913231221 is about 30219.7157663668. The cubic root of 913231221 is about 970.1977210578.

The spelling of 913231221 in words is "nine hundred thirteen million, two hundred thirty-one thousand, two hundred twenty-one".