129851989 has 2 divisors, whose sum is σ = 129851990. Its totient is φ = 129851988.

The previous prime is 129851987. The next prime is 129852007. The reversal of 129851989 is 989158921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81757764 + 48094225 = 9042^2 + 6935^2 .

It is a cyclic number.

It is not a de Polignac number, because 129851989 - 2¹ = 129851987 is a prime.

It is a super-2 number, since 2×129851989² = 33723078094512242, which contains 22 as substring.

Together with 129851987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129851983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64925994 + 64925995.

It is an arithmetic number, because the mean of its divisors is an integer number (64925995).

Almost surely, 2^129851989 is an apocalyptic number.

It is an amenable number.

129851989 is a deficient number, since it is larger than the sum of its proper divisors (1).

129851989 is an equidigital number, since it uses as much as digits as its factorization.

129851989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 52.

The square root of 129851989 is about 11395.2616907204. The cubic root of 129851989 is about 506.3873741098.

The spelling of 129851989 in words is "one hundred twenty-nine million, eight hundred fifty-one thousand, nine hundred eighty-nine".