820740 has 24 divisors (see below), whose sum is σ = 2298240. Its totient is φ = 218848.

The previous prime is 820733. The next prime is 820747. The reversal of 820740 is 47028.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (820733) and next prime (820747).

It is a super-2 number, since 2×820740² = 1347228295200, which contains 22 as substring.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (820747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6780 + ... + 6899.

It is an arithmetic number, because the mean of its divisors is an integer number (95760).

2⁸²⁰⁷⁴⁰ is an apocalyptic number.

It is an amenable number.

820740 is an abundant number, since it is smaller than the sum of its proper divisors (1477500).

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

820740 is a wasteful number, since it uses less digits than its factorization.

820740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13691 (or 13689 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 820740 is about 905.9470183184. The cubic root of 820740 is about 93.6271635677.

Adding to 820740 its reverse (47028), we get a palindrome (867768).

The spelling of 820740 in words is "eight hundred twenty thousand, seven hundred forty".