129799918 has 4 divisors (see below), whose sum is σ = 194699880. Its totient is φ = 64899958.

The previous prime is 129799867. The next prime is 129799921. The reversal of 129799918 is 819997921.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32449978 + ... + 32449981.

It is an arithmetic number, because the mean of its divisors is an integer number (48674970).

Almost surely, 2^129799918 is an apocalyptic number.

129799918 is a deficient number, since it is larger than the sum of its proper divisors (64899962).

129799918 is an equidigital number, since it uses as much as digits as its factorization.

129799918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64899961.

The product of its digits is 734832, while the sum is 55.

The square root of 129799918 is about 11392.9766961931. The cubic root of 129799918 is about 506.3196774898.

The spelling of 129799918 in words is "one hundred twenty-nine million, seven hundred ninety-nine thousand, nine hundred eighteen".