947872221 has 16 divisors (see below), whose sum is σ = 1315450560. Its totient is φ = 606372480.

The previous prime is 947872217. The next prime is 947872231. The reversal of 947872221 is 122278749.

It is not a de Polignac number, because 947872221 - 2² = 947872217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (947872231) 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 15 ways as a sum of consecutive naturals, for example, 19240 + ... + 47601.

It is an arithmetic number, because the mean of its divisors is an integer number (82215660).

Almost surely, 2^947872221 is an apocalyptic number.

It is an amenable number.

947872221 is a deficient number, since it is larger than the sum of its proper divisors (367578339).

947872221 is a wasteful number, since it uses less digits than its factorization.

947872221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67036.

The product of its digits is 112896, while the sum is 42.

The square root of 947872221 is about 30787.5335322594. The cubic root of 947872221 is about 982.3130912378.

The spelling of 947872221 in words is "nine hundred forty-seven million, eight hundred seventy-two thousand, two hundred twenty-one".