21403562503 has 2 divisors, whose sum is σ = 21403562504. Its totient is φ = 21403562502.

The previous prime is 21403562423. The next prime is 21403562527. The reversal of 21403562503 is 30526530412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21403562503 - 2¹⁷ = 21403431431 is a prime.

It is a super-2 number, since 2×21403562503² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21403562533) 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, 10701781251 + 10701781252.

It is an arithmetic number, because the mean of its divisors is an integer number (10701781252).

Almost surely, 2^21403562503 is an apocalyptic number.

21403562503 is a deficient number, since it is larger than the sum of its proper divisors (1).

21403562503 is an equidigital number, since it uses as much as digits as its factorization.

21403562503 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 31.

The spelling of 21403562503 in words is "twenty-one billion, four hundred three million, five hundred sixty-two thousand, five hundred three".