820681820 has 48 divisors (see below), whose sum is σ = 2073308160. Its totient is φ = 266566464.

The previous prime is 820681781. The next prime is 820681843. The reversal of 820681820 is 28186028.

820681820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 151604 + ... + 156923.

It is an arithmetic number, because the mean of its divisors is an integer number (43193920).

Almost surely, 2^820681820 is an apocalyptic number.

It is an amenable number.

820681820 is an abundant number, since it is smaller than the sum of its proper divisors (1252626340).

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

820681820 is a wasteful number, since it uses less digits than its factorization.

820681820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308562 (or 308560 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 820681820 is about 28647.5447464525. The cubic root of 820681820 is about 936.2495119139.

The spelling of 820681820 in words is "eight hundred twenty million, six hundred eighty-one thousand, eight hundred twenty".