129065861 has 4 divisors (see below), whose sum is σ = 130272192. Its totient is φ = 127859532.

The previous prime is 129065843. The next prime is 129065869. The reversal of 129065861 is 168560921.

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: 168560921 = 1321 ⋅127601.

It is a cyclic number.

It is not a de Polignac number, because 129065861 - 2¹⁴ = 129049477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129065869) 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, 603005 + ... + 603218.

It is an arithmetic number, because the mean of its divisors is an integer number (32568048).

Almost surely, 2^129065861 is an apocalyptic number.

It is an amenable number.

129065861 is a deficient number, since it is larger than the sum of its proper divisors (1206331).

129065861 is a wasteful number, since it uses less digits than its factorization.

129065861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206330.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 129065861 is about 11360.7156904836. The cubic root of 129065861 is about 505.3634099543.

The spelling of 129065861 in words is "one hundred twenty-nine million, sixty-five thousand, eight hundred sixty-one".