836728609 has 4 divisors (see below), whose sum is σ = 836938116. Its totient is φ = 836519104.

The previous prime is 836728603. The next prime is 836728667. The reversal of 836728609 is 906827638.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 906827638 = 2 ⋅453413819.

It can be written as a sum of positive squares in 2 ways, for example, as 274896400 + 561832209 = 16580^2 + 23703^2 .

It is a cyclic number.

It is not a de Polignac number, because 836728609 - 2³ = 836728601 is a prime.

It is a super-2 number, since 2×836728609² = 1400229530238149762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (836728601) 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, 98644 + ... + 106789.

It is an arithmetic number, because the mean of its divisors is an integer number (209234529).

Almost surely, 2^836728609 is an apocalyptic number.

It is an amenable number.

836728609 is a deficient number, since it is larger than the sum of its proper divisors (209507).

836728609 is a wasteful number, since it uses less digits than its factorization.

836728609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209506.

The product of its (nonzero) digits is 870912, while the sum is 49.

The square root of 836728609 is about 28926.2615800936. The cubic root of 836728609 is about 942.3123277847.

The spelling of 836728609 in words is "eight hundred thirty-six million, seven hundred twenty-eight thousand, six hundred nine".