997832821 has 2 divisors, whose sum is σ = 997832822. Its totient is φ = 997832820.

The previous prime is 997832807. The next prime is 997832831. The reversal of 997832821 is 128238799.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 636300625 + 361532196 = 25225^2 + 19014^2 .

It is a cyclic number.

It is not a de Polignac number, because 997832821 - 2¹¹ = 997830773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997832831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498916410 + 498916411.

It is an arithmetic number, because the mean of its divisors is an integer number (498916411).

Almost surely, 2^997832821 is an apocalyptic number.

It is an amenable number.

997832821 is a deficient number, since it is larger than the sum of its proper divisors (1).

997832821 is an equidigital number, since it uses as much as digits as its factorization.

997832821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 49.

The square root of 997832821 is about 31588.4919076552. The cubic root of 997832821 is about 999.2770845191.

The spelling of 997832821 in words is "nine hundred ninety-seven million, eight hundred thirty-two thousand, eight hundred twenty-one".