823924921 has 2 divisors, whose sum is σ = 823924922. Its totient is φ = 823924920.

The previous prime is 823924919. The next prime is 823924979. The reversal of 823924921 is 129429328.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 518199696 + 305725225 = 22764^2 + 17485^2 .

It is a cyclic number.

It is not a de Polignac number, because 823924921 - 2¹ = 823924919 is a prime.

Together with 823924919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (823924901) 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, 411962460 + 411962461.

It is an arithmetic number, because the mean of its divisors is an integer number (411962461).

Almost surely, 2^823924921 is an apocalyptic number.

It is an amenable number.

823924921 is a deficient number, since it is larger than the sum of its proper divisors (1).

823924921 is an equidigital number, since it uses as much as digits as its factorization.

823924921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 40.

The square root of 823924921 is about 28704.0924085748. The cubic root of 823924921 is about 937.4811548449.

The spelling of 823924921 in words is "eight hundred twenty-three million, nine hundred twenty-four thousand, nine hundred twenty-one".