129997889 has 16 divisors (see below), whose sum is σ = 152892288. Its totient is φ = 108231552.

The previous prime is 129997877. The next prime is 129997891. The reversal of 129997889 is 988799921.

It is not a de Polignac number, because 129997889 - 2¹² = 129993793 is a prime.

It is a super-2 number, since 2×129997889² = 33798902288912642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129997289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32339 + ... + 36135.

It is an arithmetic number, because the mean of its divisors is an integer number (9555768).

Almost surely, 2^129997889 is an apocalyptic number.

It is an amenable number.

129997889 is a deficient number, since it is larger than the sum of its proper divisors (22894399).

129997889 is an equidigital number, since it uses as much as digits as its factorization.

129997889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3944.

The product of its digits is 5878656, while the sum is 62.

The square root of 129997889 is about 11401.6616771416. The cubic root of 129997889 is about 506.5769598702.

The spelling of 129997889 in words is "one hundred twenty-nine million, nine hundred ninety-seven thousand, eight hundred eighty-nine".