820472641 has 4 divisors (see below), whose sum is σ = 820530052. Its totient is φ = 820415232.

The previous prime is 820472633. The next prime is 820472671. The reversal of 820472641 is 146274028.

It is a happy number.

820472641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 can be written as a sum of positive squares in 2 ways, for example, as 167159041 + 653313600 = 12929^2 + 25560^2 .

It is a cyclic number.

It is not a de Polignac number, because 820472641 - 2³ = 820472633 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 820472597 and 820472606.

It is not an unprimeable number, because it can be changed into a prime (820472621) 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, 11545 + ... + 42121.

It is an arithmetic number, because the mean of its divisors is an integer number (205132513).

Almost surely, 2^820472641 is an apocalyptic number.

It is an amenable number.

820472641 is a deficient number, since it is larger than the sum of its proper divisors (57411).

820472641 is a wasteful number, since it uses less digits than its factorization.

820472641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57410.

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 820472641 is about 28643.8936075388. The cubic root of 820472641 is about 936.1699600204.

The spelling of 820472641 in words is "eight hundred twenty million, four hundred seventy-two thousand, six hundred forty-one".