6812581257 has 12 divisors (see below), whose sum is σ = 10026063684. Its totient is φ = 4456027680.

The previous prime is 6812581249. The next prime is 6812581267. The reversal of 6812581257 is 7521852186.

6812581257 is a `hidden beast` number, since 6 + 8 + 12 + 581 + 2 + 57 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 4478821776 + 2333759481 = 66924^2 + 48309^2 .

It is not a de Polignac number, because 6812581257 - 2³ = 6812581249 is a prime.

It is a super-2 number, since 2×6812581257² = 92822526766455400098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6812581267) 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, 7140594 + ... + 7141547.

It is an arithmetic number, because the mean of its divisors is an integer number (835505307).

Almost surely, 2^6812581257 is an apocalyptic number.

It is an amenable number.

6812581257 is a deficient number, since it is larger than the sum of its proper divisors (3213482427).

6812581257 is a wasteful number, since it uses less digits than its factorization.

6812581257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14282200 (or 14282197 counting only the distinct ones).

The product of its digits is 268800, while the sum is 45.

The square root of 6812581257 is about 82538.3623353408. The cubic root of 6812581257 is about 1895.7041687469.

The spelling of 6812581257 in words is "six billion, eight hundred twelve million, five hundred eighty-one thousand, two hundred fifty-seven".