21399928704 has 1024 divisors, whose sum is σ = 84602880000. Its totient is φ = 5163540480.

The previous prime is 21399928691. The next prime is 21399928717. The reversal of 21399928704 is 40782999312.

It is an interprime number because it is at equal distance from previous prime (21399928691) and next prime (21399928717).

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 362710627 + ... + 362710685.

It is an arithmetic number, because the mean of its divisors is an integer number (82620000).

Almost surely, 2^21399928704 is an apocalyptic number.

21399928704 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 21399928704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42301440000).

21399928704 is an abundant number, since it is smaller than the sum of its proper divisors (63202951296).

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

21399928704 is a wasteful number, since it uses less digits than its factorization.

21399928704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 21399928704 in words is "twenty-one billion, three hundred ninety-nine million, nine hundred twenty-eight thousand, seven hundred four".