21500121633672 has 256 divisors, whose sum is σ = 59967300787200. Its totient is φ = 6368937569280.

The previous prime is 21500121633611. The next prime is 21500121633677. The reversal of 21500121633672 is 27633612100512.

It is a self number, because there is not a number n which added to its sum of digits gives 21500121633672.

It is not an unprimeable number, because it can be changed into a prime (21500121633677) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2385452238 + ... + 2385461250.

It is an arithmetic number, because the mean of its divisors is an integer number (234247268700).

Almost surely, 2^{21500121633672} is an apocalyptic number.

21500121633672 is a gapful number since it is divisible by the number (22) 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 21500121633672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29983650393600).

21500121633672 is an abundant number, since it is smaller than the sum of its proper divisors (38467179153528).

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

21500121633672 is a wasteful number, since it uses less digits than its factorization.

21500121633672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10116 (or 10112 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 39.

The spelling of 21500121633672 in words is "twenty-one trillion, five hundred billion, one hundred twenty-one million, six hundred thirty-three thousand, six hundred seventy-two".