21431767721100 has 288 divisors, whose sum is σ = 67942273416192. Its totient is φ = 5172879360000.

The previous prime is 21431767721099. The next prime is 21431767721179. The reversal of 21431767721100 is 112776713412.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2265270370 + ... + 2265279830.

It is an arithmetic number, because the mean of its divisors is an integer number (235910671584).

Almost surely, 2^{21431767721100} is an apocalyptic number.

21431767721100 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 21431767721100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33971136708096).

21431767721100 is an abundant number, since it is smaller than the sum of its proper divisors (46510505695092).

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

21431767721100 is a wasteful number, since it uses less digits than its factorization.

21431767721100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12417 (or 12410 counting only the distinct ones).

The product of its (nonzero) digits is 98784, while the sum is 42.

The spelling of 21431767721100 in words is "twenty-one trillion, four hundred thirty-one billion, seven hundred sixty-seven million, seven hundred twenty-one thousand, one hundred".