21226724736 has 384 divisors, whose sum is σ = 68435896320. Its totient is φ = 5806080000.

The previous prime is 21226724719. The next prime is 21226724737. The reversal of 21226724736 is 63742762212.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226724737) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 88077576 + ... + 88077816.

It is an arithmetic number, because the mean of its divisors is an integer number (178218480).

Almost surely, 2^21226724736 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 21226724736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34217948160).

21226724736 is an abundant number, since it is smaller than the sum of its proper divisors (47209171584).

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

21226724736 is a wasteful number, since it uses less digits than its factorization.

21226724736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454 (or 435 counting only the distinct ones).

The product of its digits is 338688, while the sum is 42.

The spelling of 21226724736 in words is "twenty-one billion, two hundred twenty-six million, seven hundred twenty-four thousand, seven hundred thirty-six".