820072909920 has 96 divisors (see below), whose sum is σ = 2818068744960. Its totient is φ = 198805552640.

The previous prime is 820072909811. The next prime is 820072909927. The reversal of 820072909920 is 29909270028.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 820072909920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820072909927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77653140 + ... + 77663699.

It is an arithmetic number, because the mean of its divisors is an integer number (29354882760).

Almost surely, 2^820072909920 is an apocalyptic number.

820072909920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

820072909920 is an abundant number, since it is smaller than the sum of its proper divisors (1997995835040).

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

820072909920 is a wasteful number, since it uses less digits than its factorization.

820072909920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155316868 (or 155316860 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 48.

The spelling of 820072909920 in words is "eight hundred twenty billion, seventy-two million, nine hundred nine thousand, nine hundred twenty".