129870 has 64 divisors (see below), whose sum is σ = 383040. Its totient is φ = 31104.

The previous prime is 129853. The next prime is 129887. The reversal of 129870 is 78921.

It is an interprime number because it is at equal distance from previous prime (129853) and next prime (129887).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3492 + ... + 3528.

It is an arithmetic number, because the mean of its divisors is an integer number (5985).

2¹²⁹⁸⁷⁰ is an apocalyptic number.

129870 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 129870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (191520).

129870 is an abundant number, since it is smaller than the sum of its proper divisors (253170).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129870 is a wasteful number, since it uses less digits than its factorization.

129870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 129870 is about 360.3748048907. The cubic root of 129870 is about 50.6410785692.

It can be divided in two parts, 129 and 870, that added together give a palindrome (999).

The spelling of 129870 in words is "one hundred twenty-nine thousand, eight hundred seventy".