129540061 has 4 divisors (see below), whose sum is σ = 148045792. Its totient is φ = 111034332.

The previous prime is 129540053. The next prime is 129540083. The reversal of 129540061 is 160045921.

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: 160045921 = 7 ⋅22863703.

It is a cyclic number.

It is not a de Polignac number, because 129540061 - 2³ = 129540053 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 (129540001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9252855 + ... + 9252868.

It is an arithmetic number, because the mean of its divisors is an integer number (37011448).

Almost surely, 2^129540061 is an apocalyptic number.

It is an amenable number.

129540061 is a deficient number, since it is larger than the sum of its proper divisors (18505731).

129540061 is an equidigital number, since it uses as much as digits as its factorization.

129540061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18505730.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 129540061 is about 11381.5667199204. The cubic root of 129540061 is about 505.9815709307.

Adding to 129540061 its reverse (160045921), we get a palindrome (289585982).

The spelling of 129540061 in words is "one hundred twenty-nine million, five hundred forty thousand, sixty-one".