129356610665 has 4 divisors (see below), whose sum is σ = 155227932804. Its totient is φ = 103485288528.

The previous prime is 129356610659. The next prime is 129356610689. The reversal of 129356610665 is 566016653921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45701460841 + 83655149824 = 213779^2 + 289232^2 .

It is a cyclic number.

It is not a de Polignac number, because 129356610665 - 2¹⁸ = 129356348521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12935661062 + ... + 12935661071.

It is an arithmetic number, because the mean of its divisors is an integer number (38806983201).

Almost surely, 2^129356610665 is an apocalyptic number.

It is an amenable number.

129356610665 is a deficient number, since it is larger than the sum of its proper divisors (25871322139).

129356610665 is an equidigital number, since it uses as much as digits as its factorization.

129356610665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25871322138.

The product of its (nonzero) digits is 1749600, while the sum is 50.

The spelling of 129356610665 in words is "one hundred twenty-nine billion, three hundred fifty-six million, six hundred ten thousand, six hundred sixty-five".