126721126129 has 8 divisors (see below), whose sum is σ = 136497829160. Its totient is φ = 116948555136.

The previous prime is 126721126121. The next prime is 126721126141. The reversal of 126721126129 is 921621127621.

It can be written as a sum of positive squares in 4 ways, for example, as 11360362225 + 115360763904 = 106585^2 + 339648^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 126721126129 - 2³ = 126721126121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 126721126091 and 126721126100.

It is not an unprimeable number, because it can be changed into a prime (126721126121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 969162 + ... + 1092115.

It is an arithmetic number, because the mean of its divisors is an integer number (17062228645).

Almost surely, 2^126721126129 is an apocalyptic number.

It is an amenable number.

126721126129 is a deficient number, since it is larger than the sum of its proper divisors (9776703031).

126721126129 is a wasteful number, since it uses less digits than its factorization.

126721126129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2066019.

The product of its digits is 36288, while the sum is 40.

The spelling of 126721126129 in words is "one hundred twenty-six billion, seven hundred twenty-one million, one hundred twenty-six thousand, one hundred twenty-nine".