812720 has 20 divisors (see below), whose sum is σ = 1889760. Its totient is φ = 325056.

The previous prime is 812717. The next prime is 812731. The reversal of 812720 is 27218.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 812692 and 812701.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5000 + ... + 5159.

It is an arithmetic number, because the mean of its divisors is an integer number (94488).

2⁸¹²⁷²⁰ is an apocalyptic number.

812720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812720 is an abundant number, since it is smaller than the sum of its proper divisors (1077040).

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

812720 is a wasteful number, since it uses less digits than its factorization.

812720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10172 (or 10166 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 812720 is about 901.5098446495. The cubic root of 812720 is about 93.3212002369.

Adding to 812720 its reverse (27218), we get a palindrome (839938).

The spelling of 812720 in words is "eight hundred twelve thousand, seven hundred twenty".