129421667 has 4 divisors (see below), whose sum is σ = 135048720. Its totient is φ = 123794616.

The previous prime is 129421639. The next prime is 129421723. The reversal of 129421667 is 766124921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 766124921 = 109 ⋅7028669.

It is a cyclic number.

It is not a de Polignac number, because 129421667 - 2¹⁶ = 129356131 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 129421667.

It is not an unprimeable number, because it can be changed into a prime (129421067) 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, 2813492 + ... + 2813537.

It is an arithmetic number, because the mean of its divisors is an integer number (33762180).

Almost surely, 2^129421667 is an apocalyptic number.

129421667 is a deficient number, since it is larger than the sum of its proper divisors (5627053).

129421667 is an equidigital number, since it uses as much as digits as its factorization.

129421667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5627052.

The product of its digits is 36288, while the sum is 38.

The square root of 129421667 is about 11376.3644016883. The cubic root of 129421667 is about 505.8273755383.

The spelling of 129421667 in words is "one hundred twenty-nine million, four hundred twenty-one thousand, six hundred sixty-seven".