129857978 has 8 divisors (see below), whose sum is σ = 194930400. Its totient is φ = 64881180.

The previous prime is 129857957. The next prime is 129858007. The reversal of 129857978 is 879758921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20408 + ... + 26003.

It is an arithmetic number, because the mean of its divisors is an integer number (24366300).

Almost surely, 2^129857978 is an apocalyptic number.

129857978 is a deficient number, since it is larger than the sum of its proper divisors (65072422).

129857978 is a wasteful number, since it uses less digits than its factorization.

129857978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47812.

The product of its digits is 2540160, while the sum is 56.

The square root of 129857978 is about 11395.5244723532. The cubic root of 129857978 is about 506.3951591462.

The spelling of 129857978 in words is "one hundred twenty-nine million, eight hundred fifty-seven thousand, nine hundred seventy-eight".