126686407681 has 4 divisors (see below), whose sum is σ = 126713650864. Its totient is φ = 126659164500.

The previous prime is 126686407667. The next prime is 126686407697. The reversal of 126686407681 is 186704686621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 186704686621 = 29221 ⋅6389401.

It is a cyclic number.

It is not a de Polignac number, because 126686407681 - 2³¹ = 124538924033 is a prime.

It is a super-2 number, since 2×126686407681² (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 (126686407651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13614615 + ... + 13623916.

It is an arithmetic number, because the mean of its divisors is an integer number (31678412716).

Almost surely, 2^126686407681 is an apocalyptic number.

It is an amenable number.

126686407681 is a deficient number, since it is larger than the sum of its proper divisors (27243183).

126686407681 is an equidigital number, since it uses as much as digits as its factorization.

126686407681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27243182.

The product of its (nonzero) digits is 4644864, while the sum is 55.

The spelling of 126686407681 in words is "one hundred twenty-six billion, six hundred eighty-six million, four hundred seven thousand, six hundred eighty-one".