129017089727761 has 3 divisors (see below), whose sum is σ = 129017101086331. Its totient is φ = 129017078369192.

The previous prime is 129017089727731. The next prime is 129017089727789. The reversal of 129017089727761 is 167727980710921.

It is a happy number.

The square root of 129017089727761 is 11358569.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 127416257470161 + 1600832257600 = 11287881^2 + 1265240^2 .

It is not a de Polignac number, because 129017089727761 - 2¹⁹ = 129017089203473 is a prime.

It is a super-2 number, since 2×129017089727761² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129017089727731) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 5679285 + ... + 17037853.

Almost surely, 2^{129017089727761} is an apocalyptic number.

129017089727761 is the 11358569-th square number.

129017089727761 is the 5679285-th centered octagonal number.

It is an amenable number.

129017089727761 is a deficient number, since it is larger than the sum of its proper divisors (11358570).

129017089727761 is an frugal number, since it uses more digits than its factorization.

129017089727761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22717138 (or 11358569 counting only the distinct ones).

The product of its (nonzero) digits is 37340352, while the sum is 67.

The spelling of 129017089727761 in words is "one hundred twenty-nine trillion, seventeen billion, eighty-nine million, seven hundred twenty-seven thousand, seven hundred sixty-one".