820781841 has 48 divisors (see below), whose sum is σ = 1289619072. Its totient is φ = 462781440.

The previous prime is 820781827. The next prime is 820781891. The reversal of 820781841 is 148187028.

It is a happy number.

It is not a de Polignac number, because 820781841 - 2¹⁰ = 820780817 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 820781841.

It is not an unprimeable number, because it can be changed into a prime (820781891) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 307585 + ... + 310241.

It is an arithmetic number, because the mean of its divisors is an integer number (26867064).

Almost surely, 2^820781841 is an apocalyptic number.

It is an amenable number.

820781841 is a deficient number, since it is larger than the sum of its proper divisors (468837231).

820781841 is a wasteful number, since it uses less digits than its factorization.

820781841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742 (or 2731 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 39.

The square root of 820781841 is about 28649.2904100608. The cubic root of 820781841 is about 936.2875456585.

The spelling of 820781841 in words is "eight hundred twenty million, seven hundred eighty-one thousand, eight hundred forty-one".