21039074784 has 480 divisors, whose sum is σ = 76716896256. Its totient is φ = 5507896320.

The previous prime is 21039074743. The next prime is 21039074801. The reversal of 21039074784 is 48747093012.

21039074784 is a `hidden beast` number, since 210 + 390 + 7 + 47 + 8 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 45051319 + ... + 45051785.

Almost surely, 2^21039074784 is an apocalyptic number.

21039074784 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 21039074784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38358448128).

21039074784 is an abundant number, since it is smaller than the sum of its proper divisors (55677821472).

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

21039074784 is a wasteful number, since it uses less digits than its factorization.

21039074784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700 (or 683 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 21039074784 in words is "twenty-one billion, thirty-nine million, seventy-four thousand, seven hundred eighty-four".