21079437853 has 2 divisors, whose sum is σ = 21079437854. Its totient is φ = 21079437852.

The previous prime is 21079437851. The next prime is 21079437947. The reversal of 21079437853 is 35873497012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15869196729 + 5210241124 = 125973^2 + 72182^2 .

It is a cyclic number.

It is not a de Polignac number, because 21079437853 - 2¹ = 21079437851 is a prime.

Together with 21079437851, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21079437797 and 21079437806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21079437851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10539718926 + 10539718927.

It is an arithmetic number, because the mean of its divisors is an integer number (10539718927).

Almost surely, 2^21079437853 is an apocalyptic number.

It is an amenable number.

21079437853 is a deficient number, since it is larger than the sum of its proper divisors (1).

21079437853 is an equidigital number, since it uses as much as digits as its factorization.

21079437853 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1270080, while the sum is 49.

The spelling of 21079437853 in words is "twenty-one billion, seventy-nine million, four hundred thirty-seven thousand, eight hundred fifty-three".