21857631447744 has 224 divisors, whose sum is σ = 65481552430080. Its totient is φ = 7237619308800.

The previous prime is 21857631447733. The next prime is 21857631447791. The reversal of 21857631447744 is 44774413675812.

21857631447744 is a `hidden beast` number, since 2 + 1 + 8 + 57 + 63 + 14 + 477 + 44 = 666.

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 31 ways as a sum of consecutive naturals, for example, 20618077 + ... + 21652259.

Almost surely, 2^{21857631447744} is an apocalyptic number.

21857631447744 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 21857631447744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32740776215040).

21857631447744 is an abundant number, since it is smaller than the sum of its proper divisors (43623920982336).

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

21857631447744 is an equidigital number, since it uses as much as digits as its factorization.

21857631447744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034367 (or 1034339 counting only the distinct ones).

The product of its digits is 126443520, while the sum is 63.

The spelling of 21857631447744 in words is "twenty-one trillion, eight hundred fifty-seven billion, six hundred thirty-one million, four hundred forty-seven thousand, seven hundred forty-four".