21402809503 has 2 divisors, whose sum is σ = 21402809504. Its totient is φ = 21402809502.

The previous prime is 21402809489. The next prime is 21402809513. The reversal of 21402809503 is 30590820412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21402809503 - 2¹³ = 21402801311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21402809513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701404751 + 10701404752.

It is an arithmetic number, because the mean of its divisors is an integer number (10701404752).

Almost surely, 2^21402809503 is an apocalyptic number.

21402809503 is a deficient number, since it is larger than the sum of its proper divisors (1).

21402809503 is an equidigital number, since it uses as much as digits as its factorization.

21402809503 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 34.

The spelling of 21402809503 in words is "twenty-one billion, four hundred two million, eight hundred nine thousand, five hundred three".