800420891 has 2 divisors, whose sum is σ = 800420892. Its totient is φ = 800420890.

The previous prime is 800420869. The next prime is 800420903. The reversal of 800420891 is 198024008.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 800420891 - 2⁶ = 800420827 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (800420591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400210445 + 400210446.

It is an arithmetic number, because the mean of its divisors is an integer number (400210446).

Almost surely, 2^800420891 is an apocalyptic number.

800420891 is a deficient number, since it is larger than the sum of its proper divisors (1).

800420891 is an equidigital number, since it uses as much as digits as its factorization.

800420891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 800420891 is about 28291.7106411048. The cubic root of 800420891 is about 928.4805384276.

Adding to 800420891 its reverse (198024008), we get a palindrome (998444899).

The spelling of 800420891 in words is "eight hundred million, four hundred twenty thousand, eight hundred ninety-one".