820902889 has 4 divisors (see below), whose sum is σ = 821779924. Its totient is φ = 820025856.

The previous prime is 820902877. The next prime is 820902947. The reversal of 820902889 is 988209028.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 503778025 + 317124864 = 22445^2 + 17808^2 .

It is a 3-Lehmer number, since φ(820902889) divides (820902889-1)³.

It is a cyclic number.

It is not a de Polignac number, because 820902889 - 2²¹ = 818805737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820902869) by changing a digit.

It is a nontrivial repunit in base 936.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 437112 + ... + 438985.

It is an arithmetic number, because the mean of its divisors is an integer number (205444981).

Almost surely, 2^820902889 is an apocalyptic number.

It is an amenable number.

820902889 is a deficient number, since it is larger than the sum of its proper divisors (877035).

820902889 is an equidigital number, since it uses as much as digits as its factorization.

820902889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877034.

The product of its (nonzero) digits is 165888, while the sum is 46.

The square root of 820902889 is about 28651.4029150407. The cubic root of 820902889 is about 936.3335709473. Note that the first 3 decimals are identical.

The spelling of 820902889 in words is "eight hundred twenty million, nine hundred two thousand, eight hundred eighty-nine".