809621491 has 8 divisors (see below), whose sum is σ = 927765344. Its totient is φ = 692098560.

The previous prime is 809621473. The next prime is 809621497. The reversal of 809621491 is 194126908.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 809621491 - 2⁷ = 809621363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (809621497) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152430 + ... + 157651.

It is an arithmetic number, because the mean of its divisors is an integer number (115970668).

Almost surely, 2^809621491 is an apocalyptic number.

809621491 is a deficient number, since it is larger than the sum of its proper divisors (118143853).

809621491 is a wasteful number, since it uses less digits than its factorization.

809621491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310461.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 809621491 is about 28453.8484391831. The cubic root of 809621491 is about 932.0245297227.

The spelling of 809621491 in words is "eight hundred nine million, six hundred twenty-one thousand, four hundred ninety-one".