129421664 has 48 divisors (see below), whose sum is σ = 266716800. Its totient is φ = 61737984.

The previous prime is 129421639. The next prime is 129421723. The reversal of 129421664 is 466124921.

It is a super-2 number, since 2×129421664² = 33499934225057792, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81809 + ... + 83375.

It is an arithmetic number, because the mean of its divisors is an integer number (5556600).

Almost surely, 2^129421664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129421664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133358400).

129421664 is an abundant number, since it is smaller than the sum of its proper divisors (137295136).

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

129421664 is a wasteful number, since it uses less digits than its factorization.

129421664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1695 (or 1687 counting only the distinct ones).

The product of its digits is 20736, while the sum is 35.

The square root of 129421664 is about 11376.3642698359. The cubic root of 129421664 is about 505.8273716299.

The spelling of 129421664 in words is "one hundred twenty-nine million, four hundred twenty-one thousand, six hundred sixty-four".