7866655640 has 32 divisors (see below), whose sum is σ = 18111606480. Its totient is φ = 3073483392.

The previous prime is 7866655613. The next prime is 7866655651. The reversal of 7866655640 is 465566687.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2285099 + ... + 2288538.

Almost surely, 2^7866655640 is an apocalyptic number.

It is an amenable number.

7866655640 is an abundant number, since it is smaller than the sum of its proper divisors (10244950840).

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

7866655640 is a wasteful number, since it uses less digits than its factorization.

7866655640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4573691 (or 4573687 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 53.

The square root of 7866655640 is about 88694.1691431855. The cubic root of 7866655640 is about 1988.8256532622.

The spelling of 7866655640 in words is "seven billion, eight hundred sixty-six million, six hundred fifty-five thousand, six hundred forty".