21712271101920 has 1536 divisors, whose sum is σ = 96258419712000. Its totient is φ = 4453718556672.

The previous prime is 21712271101849. The next prime is 21712271101933. The reversal of 21712271101920 is 2910117221712.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 3984631356 + ... + 3984636804.

It is an arithmetic number, because the mean of its divisors is an integer number (62668242000).

Almost surely, 2^{21712271101920} is an apocalyptic number.

21712271101920 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 21712271101920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48129209856000).

21712271101920 is an abundant number, since it is smaller than the sum of its proper divisors (74546148610080).

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

21712271101920 is a wasteful number, since it uses less digits than its factorization.

21712271101920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5857 (or 5843 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 36.

The spelling of 21712271101920 in words is "twenty-one trillion, seven hundred twelve billion, two hundred seventy-one million, one hundred one thousand, nine hundred twenty".