21035500253 has 2 divisors, whose sum is σ = 21035500254. Its totient is φ = 21035500252.

The previous prime is 21035500121. The next prime is 21035500259. The reversal of 21035500253 is 35200553012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19058630809 + 1976869444 = 138053^2 + 44462^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21035500253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21035500259) 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, 10517750126 + 10517750127.

It is an arithmetic number, because the mean of its divisors is an integer number (10517750127).

Almost surely, 2^21035500253 is an apocalyptic number.

It is an amenable number.

21035500253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21035500253 is an equidigital number, since it uses as much as digits as its factorization.

21035500253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4500, while the sum is 26.

The spelling of 21035500253 in words is "twenty-one billion, thirty-five million, five hundred thousand, two hundred fifty-three".