21451444353 has 16 divisors (see below), whose sum is σ = 33452545600. Its totient is φ = 13548280320.

The previous prime is 21451444321. The next prime is 21451444361. The reversal of 21451444353 is 35344415412.

21451444353 is a `hidden beast` number, since 214 + 5 + 1 + 4 + 4 + 435 + 3 = 666.

It is not a de Polignac number, because 21451444353 - 2⁵ = 21451444321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21451444253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20907328 + ... + 20908353.

It is an arithmetic number, because the mean of its divisors is an integer number (2090784100).

Almost surely, 2^21451444353 is an apocalyptic number.

It is an amenable number.

21451444353 is a deficient number, since it is larger than the sum of its proper divisors (12001101247).

21451444353 is a wasteful number, since it uses less digits than its factorization.

21451444353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41815709 (or 41815703 counting only the distinct ones).

The product of its digits is 115200, while the sum is 36.

Adding to 21451444353 its reverse (35344415412), we get a palindrome (56795859765).

The spelling of 21451444353 in words is "twenty-one billion, four hundred fifty-one million, four hundred forty-four thousand, three hundred fifty-three".