820191136 has 24 divisors (see below), whose sum is σ = 1658395620. Its totient is φ = 399011328.

The previous prime is 820191121. The next prime is 820191161. The reversal of 820191136 is 631191028.

It can be written as a sum of positive squares in 2 ways, for example, as 797723536 + 22467600 = 28244^2 + 4740^2 .

It is a junction number, because it is equal to n+sod(n) for n = 820191098 and 820191107.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 345181 + ... + 347548.

Almost surely, 2^820191136 is an apocalyptic number.

It is an amenable number.

820191136 is an abundant number, since it is smaller than the sum of its proper divisors (838204484).

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

820191136 is a wasteful number, since it uses less digits than its factorization.

820191136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692776 (or 692768 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 820191136 is about 28638.9793114210. The cubic root of 820191136 is about 936.0628808171.

The spelling of 820191136 in words is "eight hundred twenty million, one hundred ninety-one thousand, one hundred thirty-six".