21001802158080 has 936 divisors, whose sum is σ = 80176751373888. Its totient is φ = 5074665209856.

The previous prime is 21001802158079. The next prime is 21001802158109. The reversal of 21001802158080 is 8085120810012.

21001802158080 is a `hidden beast` number, since 210 + 0 + 1 + 80 + 215 + 80 + 80 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1530402099 + ... + 1530415821.

It is an arithmetic number, because the mean of its divisors is an integer number (85658922408).

Almost surely, 2^{21001802158080} is an apocalyptic number.

21001802158080 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 21001802158080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40088375686944).

21001802158080 is an abundant number, since it is smaller than the sum of its proper divisors (59174949215808).

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

21001802158080 is a wasteful number, since it uses less digits than its factorization.

21001802158080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13819 (or 13775 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 36.

Adding to 21001802158080 its reverse (8085120810012), we get a palindrome (29086922968092).

The spelling of 21001802158080 in words is "twenty-one trillion, one billion, eight hundred two million, one hundred fifty-eight thousand, eighty".