129799919 has 4 divisors (see below), whose sum is σ = 129825696. Its totient is φ = 129774144.

The previous prime is 129799867. The next prime is 129799921. The reversal of 129799919 is 919997921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 919997921 = 13241 ⋅69481.

It is a cyclic number.

It is not a de Polignac number, because 129799919 - 2¹² = 129795823 is a prime.

It is a super-2 number, since 2×129799919² = 33696037944813122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129799619) by changing a digit.

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, 2594 + ... + 16319.

It is an arithmetic number, because the mean of its divisors is an integer number (32456424).

Almost surely, 2^129799919 is an apocalyptic number.

129799919 is a deficient number, since it is larger than the sum of its proper divisors (25777).

129799919 is an equidigital number, since it uses as much as digits as its factorization.

129799919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25776.

The product of its digits is 826686, while the sum is 56.

The square root of 129799919 is about 11392.9767400798. The cubic root of 129799919 is about 506.3196787900.

The spelling of 129799919 in words is "one hundred twenty-nine million, seven hundred ninety-nine thousand, nine hundred nineteen".