808731021 has 64 divisors (see below), whose sum is σ = 1345462272. Its totient is φ = 421604352.

The previous prime is 808731013. The next prime is 808731023. The reversal of 808731021 is 120137808.

It is a happy number.

It is not a de Polignac number, because 808731021 - 2³ = 808731013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 808731021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (808731023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2634150 + ... + 2634456.

It is an arithmetic number, because the mean of its divisors is an integer number (21022848).

Almost surely, 2^808731021 is an apocalyptic number.

It is an amenable number.

808731021 is a deficient number, since it is larger than the sum of its proper divisors (536731251).

808731021 is a wasteful number, since it uses less digits than its factorization.

808731021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 808731021 is about 28438.1965145471. The cubic root of 808731021 is about 931.6827056520.

Adding to 808731021 its reverse (120137808), we get a palindrome (928868829).

The spelling of 808731021 in words is "eight hundred eight million, seven hundred thirty-one thousand, twenty-one".