21428078688 has 48 divisors (see below), whose sum is σ = 62498565360. Its totient is φ = 7142692608.

The previous prime is 21428078603. The next prime is 21428078701. The reversal of 21428078688 is 88687082412.

21428078688 is a `hidden beast` number, since 214 + 280 + 78 + 6 + 88 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12399645 + ... + 12401372.

It is an arithmetic number, because the mean of its divisors is an integer number (1302053445).

Almost surely, 2^21428078688 is an apocalyptic number.

It is an amenable number.

21428078688 is an abundant number, since it is smaller than the sum of its proper divisors (41070486672).

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

21428078688 is a wasteful number, since it uses less digits than its factorization.

21428078688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24801036 (or 24801022 counting only the distinct ones).

The product of its (nonzero) digits is 2752512, while the sum is 54.

The spelling of 21428078688 in words is "twenty-one billion, four hundred twenty-eight million, seventy-eight thousand, six hundred eighty-eight".