21749272436736 has 672 divisors, whose sum is σ = 70595586865440. Its totient is φ = 6690738143232.

The previous prime is 21749272436657. The next prime is 21749272436741. The reversal of 21749272436736 is 63763427294712.

21749272436736 is a `hidden beast` number, since 2 + 1 + 7 + 492 + 72 + 4 + 3 + 6 + 73 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4373468746 + ... + 4373473718.

It is an arithmetic number, because the mean of its divisors is an integer number (105052956645).

Almost surely, 2^{21749272436736} is an apocalyptic number.

21749272436736 is a gapful number since it is divisible by the number (26) 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 21749272436736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35297793432720).

21749272436736 is an abundant number, since it is smaller than the sum of its proper divisors (48846314428704).

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

21749272436736 is an frugal number, since it uses more digits than its factorization.

21749272436736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5053 (or 4991 counting only the distinct ones).

The product of its digits is 128024064, while the sum is 63.

The spelling of 21749272436736 in words is "twenty-one trillion, seven hundred forty-nine billion, two hundred seventy-two million, four hundred thirty-six thousand, seven hundred thirty-six".