21128567040 has 288 divisors, whose sum is σ = 85689058560. Its totient is φ = 4829331456.

The previous prime is 21128566937. The next prime is 21128567051. The reversal of 21128567040 is 4076582112.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a junction number, because it is equal to n+sod(n) for n = 21128566986 and 21128567004.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 198252 + ... + 285588.

Almost surely, 2^21128567040 is an apocalyptic number.

21128567040 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 21128567040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42844529280).

21128567040 is an abundant number, since it is smaller than the sum of its proper divisors (64560491520).

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

21128567040 is an equidigital number, since it uses as much as digits as its factorization.

21128567040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87374 (or 87354 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The spelling of 21128567040 in words is "twenty-one billion, one hundred twenty-eight million, five hundred sixty-seven thousand, forty".