6685738551 has 12 divisors (see below), whose sum is σ = 9668076912. Its totient is φ = 4452128736.

The previous prime is 6685738519. The next prime is 6685738571. The reversal of 6685738551 is 1558375866.

6685738551 is a `hidden beast` number, since 6 + 6 + 8 + 57 + 38 + 551 = 666.

It is not a de Polignac number, because 6685738551 - 2⁵ = 6685738519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6685738511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 410766 + ... + 426731.

It is an arithmetic number, because the mean of its divisors is an integer number (805673076).

Almost surely, 2^6685738551 is an apocalyptic number.

6685738551 is a deficient number, since it is larger than the sum of its proper divisors (2982338361).

6685738551 is a wasteful number, since it uses less digits than its factorization.

6685738551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 838390 (or 838387 counting only the distinct ones).

The product of its digits is 6048000, while the sum is 54.

The square root of 6685738551 is about 81766.3656462729. The cubic root of 6685738551 is about 1883.8650820595.

The spelling of 6685738551 in words is "six billion, six hundred eighty-five million, seven hundred thirty-eight thousand, five hundred fifty-one".