127835566681 has 9 divisors (see below), whose sum is σ = 132406433341. Its totient is φ = 123417432544.

The previous prime is 127835566673. The next prime is 127835566693. The reversal of 127835566681 is 186665538721.

The square root of 127835566681 is 357541.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 55936507081 + 71899059600 = 236509^2 + 268140^2 .

It is not a de Polignac number, because 127835566681 - 2³ = 127835566673 is a prime.

It is a super-2 number, since 2×127835566681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127835566081) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10362525 + ... + 10374853.

Almost surely, 2^127835566681 is an apocalyptic number.

127835566681 is the 357541-st square number.

127835566681 is the 178771-st centered octagonal number.

It is an amenable number.

127835566681 is a deficient number, since it is larger than the sum of its proper divisors (4570866660).

127835566681 is an frugal number, since it uses more digits than its factorization.

127835566681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24716 (or 12358 counting only the distinct ones).

The product of its digits is 14515200, while the sum is 58.

The spelling of 127835566681 in words is "one hundred twenty-seven billion, eight hundred thirty-five million, five hundred sixty-six thousand, six hundred eighty-one".