129240078 has 16 divisors (see below), whose sum is σ = 281978496. Its totient is φ = 39163640.

The previous prime is 129240061. The next prime is 129240079. The reversal of 129240078 is 870042921.

It is a happy number.

It is a super-2 number, since 2×129240078² = 33405995522892168, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129240079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 979026 + ... + 979157.

It is an arithmetic number, because the mean of its divisors is an integer number (17623656).

Almost surely, 2^129240078 is an apocalyptic number.

129240078 is an abundant number, since it is smaller than the sum of its proper divisors (152738418).

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

129240078 is a wasteful number, since it uses less digits than its factorization.

129240078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1958199.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 129240078 is about 11368.3806234661. The cubic root of 129240078 is about 505.5906926555.

Adding to 129240078 its reverse (870042921), we get a palindrome (999282999).

The spelling of 129240078 in words is "one hundred twenty-nine million, two hundred forty thousand, seventy-eight".