7812820 has 24 divisors (see below), whose sum is σ = 16556904. Its totient is φ = 3096576.

The previous prime is 7812797. The next prime is 7812821. The reversal of 7812820 is 282187.

It can be written as a sum of positive squares in 4 ways, for example, as 853776 + 6959044 = 924^2 + 2638^2 .

It is a super-2 number, since 2×7812820² = 122080312704800, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7812821) 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, 532 + ... + 3988.

It is an arithmetic number, because the mean of its divisors is an integer number (689871).

Almost surely, 2^7812820 is an apocalyptic number.

It is an amenable number.

7812820 is an abundant number, since it is smaller than the sum of its proper divisors (8744084).

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

7812820 is a wasteful number, since it uses less digits than its factorization.

7812820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3579 (or 3577 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 7812820 is about 2795.1422146288. The cubic root of 7812820 is about 198.4278406235.

The spelling of 7812820 in words is "seven million, eight hundred twelve thousand, eight hundred twenty".