21054444493 has 2 divisors, whose sum is σ = 21054444494. Its totient is φ = 21054444492.

The previous prime is 21054444451. The next prime is 21054444503. The reversal of 21054444493 is 39444445012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12809259684 + 8245184809 = 113178^2 + 90803^2 .

It is a cyclic number.

It is not a de Polignac number, because 21054444493 - 2²⁵ = 21020890061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21054445493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10527222246 + 10527222247.

It is an arithmetic number, because the mean of its divisors is an integer number (10527222247).

Almost surely, 2^21054444493 is an apocalyptic number.

It is an amenable number.

21054444493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21054444493 is an equidigital number, since it uses as much as digits as its factorization.

21054444493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 276480, while the sum is 40.

The spelling of 21054444493 in words is "twenty-one billion, fifty-four million, four hundred forty-four thousand, four hundred ninety-three".