828940921 has 2 divisors, whose sum is σ = 828940922. Its totient is φ = 828940920.

The previous prime is 828940919. The next prime is 828940991. The reversal of 828940921 is 129049828.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 578162025 + 250778896 = 24045^2 + 15836^2 .

It is a cyclic number.

It is not a de Polignac number, because 828940921 - 2¹ = 828940919 is a prime.

Together with 828940919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (828940991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 414470460 + 414470461.

It is an arithmetic number, because the mean of its divisors is an integer number (414470461).

Almost surely, 2^828940921 is an apocalyptic number.

It is an amenable number.

828940921 is a deficient number, since it is larger than the sum of its proper divisors (1).

828940921 is an equidigital number, since it uses as much as digits as its factorization.

828940921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 828940921 is about 28791.3341302552. The cubic root of 828940921 is about 939.3797481325.

The spelling of 828940921 in words is "eight hundred twenty-eight million, nine hundred forty thousand, nine hundred twenty-one".