7820645 has 24 divisors (see below), whose sum is σ = 11043864. Its totient is φ = 5300736.

The previous prime is 7820639. The next prime is 7820669. The reversal of 7820645 is 5460287.

It can be written as a sum of positive squares in 4 ways, for example, as 329476 + 7491169 = 574^2 + 2737^2 .

It is not a de Polignac number, because 7820645 - 2⁶ = 7820581 is a prime.

It is a super-2 number, since 2×7820645² = 122324976432050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33449 + ... + 33681.

It is an arithmetic number, because the mean of its divisors is an integer number (460161).

Almost surely, 2^7820645 is an apocalyptic number.

It is an amenable number.

7820645 is a deficient number, since it is larger than the sum of its proper divisors (3223219).

7820645 is a wasteful number, since it uses less digits than its factorization.

7820645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389 (or 382 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 7820645 is about 2796.5416142085. The cubic root of 7820645 is about 198.4940642478.

The spelling of 7820645 in words is "seven million, eight hundred twenty thousand, six hundred forty-five".