129721846 has 16 divisors (see below), whose sum is σ = 198838800. Its totient is φ = 63449568.

The previous prime is 129721831. The next prime is 129721847. The reversal of 129721846 is 648127921.

It is a junction number, because it is equal to n+sod(n) for n = 129721799 and 129721808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129721847) 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 7 ways as a sum of consecutive naturals, for example, 38560 + ... + 41788.

It is an arithmetic number, because the mean of its divisors is an integer number (12427425).

Almost surely, 2^129721846 is an apocalyptic number.

129721846 is a deficient number, since it is larger than the sum of its proper divisors (69116954).

129721846 is a wasteful number, since it uses less digits than its factorization.

129721846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3663.

The product of its digits is 48384, while the sum is 40.

The square root of 129721846 is about 11389.5498594106. The cubic root of 129721846 is about 506.2181434814.

The spelling of 129721846 in words is "one hundred twenty-nine million, seven hundred twenty-one thousand, eight hundred forty-six".