21871512000 has 448 divisors, whose sum is σ = 86427868800. Its totient is φ = 5383065600.

The previous prime is 21871511999. The next prime is 21871512011. The reversal of 21871512000 is 21517812.

It is a super-2 number, since 2×21871512000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2804106 + ... + 2811894.

It is an arithmetic number, because the mean of its divisors is an integer number (192919350).

Almost surely, 2^21871512000 is an apocalyptic number.

21871512000 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 21871512000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43213934400).

21871512000 is an abundant number, since it is smaller than the sum of its proper divisors (64556356800).

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

21871512000 is a wasteful number, since it uses less digits than its factorization.

21871512000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7838 (or 7812 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The spelling of 21871512000 in words is "twenty-one billion, eight hundred seventy-one million, five hundred twelve thousand".