21021042503 has 2 divisors, whose sum is σ = 21021042504. Its totient is φ = 21021042502.

The previous prime is 21021042499. The next prime is 21021042541. The reversal of 21021042503 is 30524012012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21021042503 - 2² = 21021042499 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021042703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510521251 + 10510521252.

It is an arithmetic number, because the mean of its divisors is an integer number (10510521252).

Almost surely, 2^21021042503 is an apocalyptic number.

21021042503 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021042503 is an equidigital number, since it uses as much as digits as its factorization.

21021042503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 21021042503 its reverse (30524012012), we get a palindrome (51545054515).

The spelling of 21021042503 in words is "twenty-one billion, twenty-one million, forty-two thousand, five hundred three".