21398478853 has 2 divisors, whose sum is σ = 21398478854. Its totient is φ = 21398478852.

The previous prime is 21398478839. The next prime is 21398478863. The reversal of 21398478853 is 35887489312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16884923364 + 4513555489 = 129942^2 + 67183^2 .

It is a cyclic number.

It is not a de Polignac number, because 21398478853 - 2⁵ = 21398478821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21398478863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10699239426 + 10699239427.

It is an arithmetic number, because the mean of its divisors is an integer number (10699239427).

Almost surely, 2^21398478853 is an apocalyptic number.

It is an amenable number.

21398478853 is a deficient number, since it is larger than the sum of its proper divisors (1).

21398478853 is an equidigital number, since it uses as much as digits as its factorization.

21398478853 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11612160, while the sum is 58.

The spelling of 21398478853 in words is "twenty-one billion, three hundred ninety-eight million, four hundred seventy-eight thousand, eight hundred fifty-three".