129821808 has 40 divisors (see below), whose sum is σ = 339152400. Its totient is φ = 42786304.

The previous prime is 129821807. The next prime is 129821827. The reversal of 129821808 is 808128921.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129821801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10923 + ... + 19466.

It is an arithmetic number, because the mean of its divisors is an integer number (8478810).

Almost surely, 2^129821808 is an apocalyptic number.

It is an amenable number.

129821808 is an abundant number, since it is smaller than the sum of its proper divisors (209330592).

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

129821808 is a wasteful number, since it uses less digits than its factorization.

129821808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30489 (or 30483 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 39.

The square root of 129821808 is about 11393.9373352674. The cubic root of 129821808 is about 506.3481385112.

The spelling of 129821808 in words is "one hundred twenty-nine million, eight hundred twenty-one thousand, eight hundred eight".