820691603 has 4 divisors (see below), whose sum is σ = 820778400. Its totient is φ = 820604808.

The previous prime is 820691587. The next prime is 820691687. The reversal of 820691603 is 306196028.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 820691603 - 2⁴ = 820691587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820691693) 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, 27200 + ... + 48797.

It is an arithmetic number, because the mean of its divisors is an integer number (205194600).

Almost surely, 2^820691603 is an apocalyptic number.

820691603 is a deficient number, since it is larger than the sum of its proper divisors (86797).

820691603 is a wasteful number, since it uses less digits than its factorization.

820691603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86796.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 820691603 is about 28647.7154935607. The cubic root of 820691603 is about 936.2532321102.

The spelling of 820691603 in words is "eight hundred twenty million, six hundred ninety-one thousand, six hundred three".