820826661 has 4 divisors (see below), whose sum is σ = 1094435552. Its totient is φ = 547217772.

The previous prime is 820826627. The next prime is 820826663. The reversal of 820826661 is 166628028.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 820826661 - 2⁶ = 820826597 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 (820826663) 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, 136804441 + ... + 136804446.

It is an arithmetic number, because the mean of its divisors is an integer number (273608888).

Almost surely, 2^820826661 is an apocalyptic number.

It is an amenable number.

820826661 is a deficient number, since it is larger than the sum of its proper divisors (273608891).

820826661 is a wasteful number, since it uses less digits than its factorization.

820826661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273608890.

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 820826661 is about 28650.0726177090. The cubic root of 820826661 is about 936.3045878013.

The spelling of 820826661 in words is "eight hundred twenty million, eight hundred twenty-six thousand, six hundred sixty-one".