808016921 has 4 divisors (see below), whose sum is σ = 808092432. Its totient is φ = 807941412.

The previous prime is 808016899. The next prime is 808016947. The reversal of 808016921 is 129610808.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-808016921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (808018921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18395 + ... + 44208.

It is an arithmetic number, because the mean of its divisors is an integer number (202023108).

Almost surely, 2^808016921 is an apocalyptic number.

It is an amenable number.

808016921 is a deficient number, since it is larger than the sum of its proper divisors (75511).

808016921 is a wasteful number, since it uses less digits than its factorization.

808016921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75510.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 808016921 is about 28425.6384448969. The cubic root of 808016921 is about 931.4084032693.

The spelling of 808016921 in words is "eight hundred eight million, sixteen thousand, nine hundred twenty-one".