20129688 has 64 divisors (see below), whose sum is σ = 57304800. Its totient is φ = 6543360.

The previous prime is 20129687. The next prime is 20129713. The reversal of 20129688 is 88692102.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20129687) 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, 7720 + ... + 9992.

Almost surely, 2^20129688 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 20129688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28652400).

20129688 is an abundant number, since it is smaller than the sum of its proper divisors (37175112).

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

20129688 is a wasteful number, since it uses less digits than its factorization.

20129688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2329 (or 2319 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 20129688 is about 4486.6120848587. The cubic root of 20129688 is about 272.0272103690.

The spelling of 20129688 in words is "twenty million, one hundred twenty-nine thousand, six hundred eighty-eight".