7880665 has 16 divisors (see below), whose sum is σ = 10515456. Its totient is φ = 5630400.

The previous prime is 7880659. The next prime is 7880671. The reversal of 7880665 is 5660887.

7880665 = 144² + 145² + ... + 298².

It is an interprime number because it is at equal distance from previous prime (7880659) and next prime (7880671).

It is not a de Polignac number, because 7880665 - 2⁹ = 7880153 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60 + ... + 3970.

It is an arithmetic number, because the mean of its divisors is an integer number (657216).

Almost surely, 2^7880665 is an apocalyptic number.

It is an amenable number.

7880665 is a deficient number, since it is larger than the sum of its proper divisors (2634791).

7880665 is a wasteful number, since it uses less digits than its factorization.

7880665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3960.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 7880665 is about 2807.2522152454. The cubic root of 7880665 is about 199.0005555400. Note that the first 3 decimals are identical.

The spelling of 7880665 in words is "seven million, eight hundred eighty thousand, six hundred sixty-five".