21129684000 has 192 divisors, whose sum is σ = 70832361600. Its totient is φ = 5503411200.

The previous prime is 21129683947. The next prime is 21129684011. The reversal of 21129684000 is 48692112.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 495526 + ... + 536474.

It is an arithmetic number, because the mean of its divisors is an integer number (368918550).

Almost surely, 2^21129684000 is an apocalyptic number.

21129684000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21129684000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35416180800).

21129684000 is an abundant number, since it is smaller than the sum of its proper divisors (49702677600).

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

21129684000 is a wasteful number, since it uses less digits than its factorization.

21129684000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41020 (or 41002 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

It can be divided in two parts, 211296 and 84000, that added together give a triangular number (295296 = T₇₆₈).

The spelling of 21129684000 in words is "twenty-one billion, one hundred twenty-nine million, six hundred eighty-four thousand".