21393052128 has 384 divisors, whose sum is σ = 76001587200. Its totient is φ = 5718283776.

The previous prime is 21393052117. The next prime is 21393052141. The reversal of 21393052128 is 82125039312.

21393052128 is a `hidden beast` number, since 2 + 139 + 305 + 212 + 8 = 666.

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 = 21393052092 and 21393052101.

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, 9536575 + ... + 9538817.

It is an arithmetic number, because the mean of its divisors is an integer number (197920800).

Almost surely, 2^21393052128 is an apocalyptic number.

21393052128 is a gapful number since it is divisible by the number (28) 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 21393052128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38000793600).

21393052128 is an abundant number, since it is smaller than the sum of its proper divisors (54608535072).

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

21393052128 is a wasteful number, since it uses less digits than its factorization.

21393052128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371 (or 2357 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 21393052128 in words is "twenty-one billion, three hundred ninety-three million, fifty-two thousand, one hundred twenty-eight".