129423641 has 4 divisors (see below), whose sum is σ = 129494400. Its totient is φ = 129352884.

The previous prime is 129423631. The next prime is 129423661. The reversal of 129423641 is 146324921.

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: 146324921 = 1787 ⋅81883.

It is a cyclic number.

It is not a de Polignac number, because 129423641 - 2⁶ = 129423577 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 129423598 and 129423607.

It is not an unprimeable number, because it can be changed into a prime (129423631) 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, 32561 + ... + 36318.

It is an arithmetic number, because the mean of its divisors is an integer number (32373600).

Almost surely, 2^129423641 is an apocalyptic number.

It is an amenable number.

129423641 is a deficient number, since it is larger than the sum of its proper divisors (70759).

129423641 is an equidigital number, since it uses as much as digits as its factorization.

129423641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70758.

The product of its digits is 10368, while the sum is 32.

The square root of 129423641 is about 11376.4511601817. The cubic root of 129423641 is about 505.8299472307.

The spelling of 129423641 in words is "one hundred twenty-nine million, four hundred twenty-three thousand, six hundred forty-one".