804940921 has 2 divisors, whose sum is σ = 804940922. Its totient is φ = 804940920.

The previous prime is 804940919. The next prime is 804940963. The reversal of 804940921 is 129049408.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 747256896 + 57684025 = 27336^2 + 7595^2 .

It is a cyclic number.

It is not a de Polignac number, because 804940921 - 2¹ = 804940919 is a prime.

Together with 804940919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (804943921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402470460 + 402470461.

It is an arithmetic number, because the mean of its divisors is an integer number (402470461).

Almost surely, 2^804940921 is an apocalyptic number.

It is an amenable number.

804940921 is a deficient number, since it is larger than the sum of its proper divisors (1).

804940921 is an equidigital number, since it uses as much as digits as its factorization.

804940921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 804940921 is about 28371.4807685464. The cubic root of 804940921 is about 930.2249893083.

The spelling of 804940921 in words is "eight hundred four million, nine hundred forty thousand, nine hundred twenty-one".