21869171280 has 480 divisors, whose sum is σ = 86302869120. Its totient is φ = 4903403520.

The previous prime is 21869171251. The next prime is 21869171281. The reversal of 21869171280 is 8217196812.

21869171280 is a `hidden beast` number, since 218 + 6 + 91 + 71 + 280 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21869171281) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7942384 + ... + 7945136.

It is an arithmetic number, because the mean of its divisors is an integer number (179797644).

Almost surely, 2^21869171280 is an apocalyptic number.

21869171280 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 21869171280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43151434560).

21869171280 is an abundant number, since it is smaller than the sum of its proper divisors (64433697840).

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

21869171280 is a wasteful number, since it uses less digits than its factorization.

21869171280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2859 (or 2850 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The spelling of 21869171280 in words is "twenty-one billion, eight hundred sixty-nine million, one hundred seventy-one thousand, two hundred eighty".