129821742 has 12 divisors (see below), whose sum is σ = 281280480. Its totient is φ = 43273908.

The previous prime is 129821723. The next prime is 129821743. The reversal of 129821742 is 247128921.

It is a junction number, because it is equal to n+sod(n) for n = 129821697 and 129821706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129821743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3606142 + ... + 3606177.

It is an arithmetic number, because the mean of its divisors is an integer number (23440040).

Almost surely, 2^129821742 is an apocalyptic number.

129821742 is an abundant number, since it is smaller than the sum of its proper divisors (151458738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129821742 is a wasteful number, since it uses less digits than its factorization.

129821742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7212327 (or 7212324 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 129821742 is about 11393.9344389899. The cubic root of 129821742 is about 506.3480527039.

The spelling of 129821742 in words is "one hundred twenty-nine million, eight hundred twenty-one thousand, seven hundred forty-two".