6631385787 has 32 divisors (see below), whose sum is σ = 10603396160. Its totient is φ = 4071824640.

The previous prime is 6631385767. The next prime is 6631385807. The reversal of 6631385787 is 7875831366.

6631385787 is a `hidden beast` number, since 6 + 6 + 31 + 38 + 578 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (6631385767) and next prime (6631385807).

It is not a de Polignac number, because 6631385787 - 2¹⁰ = 6631384763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6631385767) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139737 + ... + 181077.

It is an arithmetic number, because the mean of its divisors is an integer number (331356130).

Almost surely, 2^6631385787 is an apocalyptic number.

6631385787 is a deficient number, since it is larger than the sum of its proper divisors (3972010373).

6631385787 is a wasteful number, since it uses less digits than its factorization.

6631385787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41820 (or 41814 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The square root of 6631385787 is about 81433.3211099732. The cubic root of 6631385787 is about 1878.7461258640.

It can be divided in two parts, 66313 and 85787, that added together give a square (152100 = 390²).

The spelling of 6631385787 in words is "six billion, six hundred thirty-one million, three hundred eighty-five thousand, seven hundred eighty-seven".