811401509 has 4 divisors (see below), whose sum is σ = 811532460. Its totient is φ = 811270560.

The previous prime is 811401499. The next prime is 811401511. The reversal of 811401509 is 905104118.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 364924609 + 446476900 = 19103^2 + 21130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-811401509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811401589) 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 3 ways as a sum of consecutive naturals, for example, 55694 + ... + 68735.

It is an arithmetic number, because the mean of its divisors is an integer number (202883115).

Almost surely, 2^811401509 is an apocalyptic number.

It is an amenable number.

811401509 is a deficient number, since it is larger than the sum of its proper divisors (130951).

811401509 is a wasteful number, since it uses less digits than its factorization.

811401509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130950.

The product of its (nonzero) digits is 1440, while the sum is 29.

The square root of 811401509 is about 28485.1103034550. The cubic root of 811401509 is about 932.7070734013.

The spelling of 811401509 in words is "eight hundred eleven million, four hundred one thousand, five hundred nine".