6861539257 has 2 divisors, whose sum is σ = 6861539258. Its totient is φ = 6861539256.

The previous prime is 6861539249. The next prime is 6861539291. The reversal of 6861539257 is 7529351686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6494586921 + 366952336 = 80589^2 + 19156^2 .

It is a cyclic number.

It is not a de Polignac number, because 6861539257 - 2³ = 6861539249 is a prime.

It is a super-2 number, since 2×6861539257² = 94161441950704224098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6861539227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3430769628 + 3430769629.

It is an arithmetic number, because the mean of its divisors is an integer number (3430769629).

Almost surely, 2^6861539257 is an apocalyptic number.

It is an amenable number.

6861539257 is a deficient number, since it is larger than the sum of its proper divisors (1).

6861539257 is an equidigital number, since it uses as much as digits as its factorization.

6861539257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2721600, while the sum is 52.

The square root of 6861539257 is about 82834.4086536507. The cubic root of 6861539257 is about 1900.2344361693.

The spelling of 6861539257 in words is "six billion, eight hundred sixty-one million, five hundred thirty-nine thousand, two hundred fifty-seven".