129918889 has 4 divisors (see below), whose sum is σ = 130116100. Its totient is φ = 129721680.

The previous prime is 129918871. The next prime is 129918931. The reversal of 129918889 is 988819921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988819921 = 751 ⋅1316671.

It can be written as a sum of positive squares in 2 ways, for example, as 67240000 + 62678889 = 8200^2 + 7917^2 .

It is a cyclic number.

It is not a de Polignac number, because 129918889 - 2⁹ = 129918377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129918809) 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, 97614 + ... + 98935.

It is an arithmetic number, because the mean of its divisors is an integer number (32529025).

Almost surely, 2^129918889 is an apocalyptic number.

It is an amenable number.

129918889 is a deficient number, since it is larger than the sum of its proper divisors (197211).

129918889 is an equidigital number, since it uses as much as digits as its factorization.

129918889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197210.

The product of its digits is 746496, while the sum is 55.

The square root of 129918889 is about 11398.1967433450. The cubic root of 129918889 is about 506.4743231030.

The spelling of 129918889 in words is "one hundred twenty-nine million, nine hundred eighteen thousand, eight hundred eighty-nine".