129661501 has 4 divisors (see below), whose sum is σ = 129753792. Its totient is φ = 129569212.

The previous prime is 129661457. The next prime is 129661513. The reversal of 129661501 is 105166921.

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: 105166921 = 157 ⋅669853.

It is a cyclic number.

It is not a de Polignac number, because 129661501 - 2¹³ = 129653309 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 (129661531) 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, 44005 + ... + 46858.

It is an arithmetic number, because the mean of its divisors is an integer number (32438448).

Almost surely, 2^129661501 is an apocalyptic number.

It is an amenable number.

129661501 is a deficient number, since it is larger than the sum of its proper divisors (92291).

129661501 is an equidigital number, since it uses as much as digits as its factorization.

129661501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92290.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 129661501 is about 11386.9004123159. The cubic root of 129661501 is about 506.1396358312.

The spelling of 129661501 in words is "one hundred twenty-nine million, six hundred sixty-one thousand, five hundred one".