21315571200 has 1440 divisors, whose sum is σ = 99736116480. Its totient is φ = 4379443200.

The previous prime is 21315571169. The next prime is 21315571219. The reversal of 21315571200 is 217551312.

It is a tau number, because it is divible by the number of its divisors (1440).

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 143 ways as a sum of consecutive naturals, for example, 239500756 + ... + 239500844.

It is an arithmetic number, because the mean of its divisors is an integer number (69261192).

Almost surely, 2^21315571200 is an apocalyptic number.

21315571200 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 21315571200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49868058240).

21315571200 is an abundant number, since it is smaller than the sum of its proper divisors (78420545280).

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

21315571200 is an equidigital number, since it uses as much as digits as its factorization.

21315571200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The spelling of 21315571200 in words is "twenty-one billion, three hundred fifteen million, five hundred seventy-one thousand, two hundred".