899869021 has 2 divisors, whose sum is σ = 899869022. Its totient is φ = 899869020.

The previous prime is 899868989. The next prime is 899869049. The reversal of 899869021 is 120968998.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 745836100 + 154032921 = 27310^2 + 12411^2 .

It is a cyclic number.

It is not a de Polignac number, because 899869021 - 2⁵ = 899868989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 899869021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (899869081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 449934510 + 449934511.

It is an arithmetic number, because the mean of its divisors is an integer number (449934511).

Almost surely, 2^899869021 is an apocalyptic number.

It is an amenable number.

899869021 is a deficient number, since it is larger than the sum of its proper divisors (1).

899869021 is an equidigital number, since it uses as much as digits as its factorization.

899869021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 559872, while the sum is 52.

The square root of 899869021 is about 29997.8169372373. The cubic root of 899869021 is about 965.4425457281.

The spelling of 899869021 in words is "eight hundred ninety-nine million, eight hundred sixty-nine thousand, twenty-one".