21389306835204 has 288 divisors, whose sum is σ = 69984372197376. Its totient is φ = 5549383457280.

The previous prime is 21389306835181. The next prime is 21389306835209. The reversal of 21389306835204 is 40253860398312.

21389306835204 is a `hidden beast` number, since 2 + 1 + 3 + 8 + 9 + 30 + 6 + 83 + 520 + 4 = 666.

It is a super-3 number, since 3×21389306835204³ (a number of 41 digits) contains 333 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21389306835209) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 66225532 + ... + 66547724.

It is an arithmetic number, because the mean of its divisors is an integer number (243001292352).

Almost surely, 2^{21389306835204} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21389306835204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34992186098688).

21389306835204 is an abundant number, since it is smaller than the sum of its proper divisors (48595065362172).

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

21389306835204 is a wasteful number, since it uses less digits than its factorization.

21389306835204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323117 (or 323103 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 21389306835204 in words is "twenty-one trillion, three hundred eighty-nine billion, three hundred six million, eight hundred thirty-five thousand, two hundred four".