912747221 has 4 divisors (see below), whose sum is σ = 966438252. Its totient is φ = 859056192.

The previous prime is 912747163. The next prime is 912747259. The reversal of 912747221 is 122747219.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 854392900 + 58354321 = 29230^2 + 7639^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-912747221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (912747271) 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, 26845490 + ... + 26845523.

It is an arithmetic number, because the mean of its divisors is an integer number (241609563).

Almost surely, 2^912747221 is an apocalyptic number.

It is an amenable number.

912747221 is a deficient number, since it is larger than the sum of its proper divisors (53691031).

912747221 is a wasteful number, since it uses less digits than its factorization.

912747221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53691030.

The product of its digits is 14112, while the sum is 35.

The square root of 912747221 is about 30211.7066879711. The cubic root of 912747221 is about 970.0262936154.

The spelling of 912747221 in words is "nine hundred twelve million, seven hundred forty-seven thousand, two hundred twenty-one".