21443515000 has 80 divisors (see below), whose sum is σ = 51311700000. Its totient is φ = 8394816000.

The previous prime is 21443514973. The next prime is 21443515039. The reversal of 21443515000 is 51534412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 189376 + ... + 280624.

It is an arithmetic number, because the mean of its divisors is an integer number (641396250).

Almost surely, 2^21443515000 is an apocalyptic number.

21443515000 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 21443515000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25655850000).

21443515000 is an abundant number, since it is smaller than the sum of its proper divisors (29868185000).

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

21443515000 is an equidigital number, since it uses as much as digits as its factorization.

21443515000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91322 (or 91303 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 21443515000 in words is "twenty-one billion, four hundred forty-three million, five hundred fifteen thousand".