129796921 has 16 divisors (see below), whose sum is σ = 140451840. Its totient is φ = 119508480.

The previous prime is 129796897. The next prime is 129796967. The reversal of 129796921 is 129697921.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 129796921 - 2²¹ = 127699769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129796021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170181 + ... + 170941.

It is an arithmetic number, because the mean of its divisors is an integer number (8778240).

Almost surely, 2^129796921 is an apocalyptic number.

It is an amenable number.

129796921 is a deficient number, since it is larger than the sum of its proper divisors (10654919).

129796921 is a wasteful number, since it uses less digits than its factorization.

129796921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984.

The product of its digits is 122472, while the sum is 46.

The square root of 129796921 is about 11392.8451670336. The cubic root of 129796921 is about 506.3157805901.

It can be divided in two parts, 12979 and 6921, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 129796921 in words is "one hundred twenty-nine million, seven hundred ninety-six thousand, nine hundred twenty-one".