820999760 has 80 divisors (see below), whose sum is σ = 2228000256. Its totient is φ = 275487744.

The previous prime is 820999759. The next prime is 820999769. The reversal of 820999760 is 67999028.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 820999699 and 820999708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820999769) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10724 + ... + 41916.

Almost surely, 2^820999760 is an apocalyptic number.

820999760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820999760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1114000128).

820999760 is an abundant number, since it is smaller than the sum of its proper divisors (1407000496).

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

820999760 is a wasteful number, since it uses less digits than its factorization.

820999760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31260 (or 31254 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 820999760 is about 28653.0933757596. The cubic root of 820999760 is about 936.3704003145.

The spelling of 820999760 in words is "eight hundred twenty million, nine hundred ninety-nine thousand, seven hundred sixty".