21128346624 has 352 divisors, whose sum is σ = 70744320000. Its totient is φ = 5446287360.

The previous prime is 21128346611. The next prime is 21128346649. The reversal of 21128346624 is 42664382112.

It is a tau number, because it is divible by the number of its divisors (352).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

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, 42341127 + ... + 42341625.

Almost surely, 2^21128346624 is an apocalyptic number.

21128346624 is a gapful number since it is divisible by the number (24) 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 21128346624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35372160000).

21128346624 is an abundant number, since it is smaller than the sum of its proper divisors (49615973376).

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

21128346624 is a wasteful number, since it uses less digits than its factorization.

21128346624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 719 (or 701 counting only the distinct ones).

The product of its digits is 110592, while the sum is 39.

The spelling of 21128346624 in words is "twenty-one billion, one hundred twenty-eight million, three hundred forty-six thousand, six hundred twenty-four".