21253421566443 has 32 divisors (see below), whose sum is σ = 31439000862720. Its totient is φ = 12662152835360.

The previous prime is 21253421566423. The next prime is 21253421566453. The reversal of 21253421566443 is 34466512435212.

It is a cyclic number.

It is not a de Polignac number, because 21253421566443 - 2⁵ = 21253421566411 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21253421566392 and 21253421566401.

It is not an unprimeable number, because it can be changed into a prime (21253421566423) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 70968646 + ... + 71267492.

It is an arithmetic number, because the mean of its divisors is an integer number (982468776960).

Almost surely, 2^{21253421566443} is an apocalyptic number.

21253421566443 is a deficient number, since it is larger than the sum of its proper divisors (10185579296277).

21253421566443 is a wasteful number, since it uses less digits than its factorization.

21253421566443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335447.

The product of its digits is 4147200, while the sum is 48.

The spelling of 21253421566443 in words is "twenty-one trillion, two hundred fifty-three billion, four hundred twenty-one million, five hundred sixty-six thousand, four hundred forty-three".