947938821 has 16 divisors (see below), whose sum is σ = 1283195520. Its totient is φ = 622341440.

The previous prime is 947938777. The next prime is 947938837. The reversal of 947938821 is 128839749.

It is a cyclic number.

It is not a de Polignac number, because 947938821 - 2¹⁸ = 947676677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (947930821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234211 + ... + 238223.

It is an arithmetic number, because the mean of its divisors is an integer number (80199720).

Almost surely, 2^947938821 is an apocalyptic number.

It is an amenable number.

947938821 is a deficient number, since it is larger than the sum of its proper divisors (335256699).

947938821 is a wasteful number, since it uses less digits than its factorization.

947938821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5196.

The product of its digits is 870912, while the sum is 51.

The square root of 947938821 is about 30788.6151198783. The cubic root of 947938821 is about 982.3360973344.

The spelling of 947938821 in words is "nine hundred forty-seven million, nine hundred thirty-eight thousand, eight hundred twenty-one".