809642736 has 80 divisors (see below), whose sum is σ = 2655980800. Its totient is φ = 231325632.

The previous prime is 809642651. The next prime is 809642741. The reversal of 809642736 is 637246908.

It is a junction number, because it is equal to n+sod(n) for n = 809642691 and 809642700.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 130846 + ... + 136893.

It is an arithmetic number, because the mean of its divisors is an integer number (33199760).

Almost surely, 2^809642736 is an apocalyptic number.

It is an amenable number.

809642736 is an abundant number, since it is smaller than the sum of its proper divisors (1846338064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

809642736 is a wasteful number, since it uses less digits than its factorization.

809642736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267763 (or 267751 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 809642736 is about 28454.2217605754. The cubic root of 809642736 is about 932.0326819635.

It can be divided in two parts, 809 and 642736, that added together give a triangular number (643545 = T₁₁₃₄).

The spelling of 809642736 in words is "eight hundred nine million, six hundred forty-two thousand, seven hundred thirty-six".