210985638653 has 2 divisors, whose sum is σ = 210985638654. Its totient is φ = 210985638652.

The previous prime is 210985638593. The next prime is 210985638659. The reversal of 210985638653 is 356836589012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209198293924 + 1787344729 = 457382^2 + 42277^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210985638653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210985638659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105492819326 + 105492819327.

It is an arithmetic number, because the mean of its divisors is an integer number (105492819327).

Almost surely, 2^210985638653 is an apocalyptic number.

It is an amenable number.

210985638653 is a deficient number, since it is larger than the sum of its proper divisors (1).

210985638653 is an equidigital number, since it uses as much as digits as its factorization.

210985638653 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9331200, while the sum is 56.

The spelling of 210985638653 in words is "two hundred ten billion, nine hundred eighty-five million, six hundred thirty-eight thousand, six hundred fifty-three".