847991221 has 8 divisors (see below), whose sum is σ = 1057235904. Its totient is φ = 660772320.

The previous prime is 847991203. The next prime is 847991227. The reversal of 847991221 is 122199748.

It is a happy number.

847991221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 847991221 - 2⁵ = 847991189 is a prime.

It is a super-2 number, since 2×847991221² = 1438178221786141682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (847991227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5506360 + ... + 5506513.

It is an arithmetic number, because the mean of its divisors is an integer number (132154488).

Almost surely, 2^847991221 is an apocalyptic number.

It is an amenable number.

847991221 is a deficient number, since it is larger than the sum of its proper divisors (209244683).

847991221 is a wasteful number, since it uses less digits than its factorization.

847991221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11012891.

The product of its digits is 72576, while the sum is 43.

The square root of 847991221 is about 29120.2888206831. The cubic root of 847991221 is about 946.5214318927.

The spelling of 847991221 in words is "eight hundred forty-seven million, nine hundred ninety-one thousand, two hundred twenty-one".