947395721 has 2 divisors, whose sum is σ = 947395722. Its totient is φ = 947395720.

The previous prime is 947395663. The next prime is 947395747. The reversal of 947395721 is 127593749.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 657204496 + 290191225 = 25636^2 + 17035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-947395721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (947395621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 473697860 + 473697861.

It is an arithmetic number, because the mean of its divisors is an integer number (473697861).

Almost surely, 2^947395721 is an apocalyptic number.

It is an amenable number.

947395721 is a deficient number, since it is larger than the sum of its proper divisors (1).

947395721 is an equidigital number, since it uses as much as digits as its factorization.

947395721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 476280, while the sum is 47.

The square root of 947395721 is about 30779.7940376475. The cubic root of 947395721 is about 982.1484591163.

The spelling of 947395721 in words is "nine hundred forty-seven million, three hundred ninety-five thousand, seven hundred twenty-one".