21042502403 has 24 divisors (see below), whose sum is σ = 24632594448. Its totient is φ = 17855986176.

The previous prime is 21042502387. The next prime is 21042502417. The reversal of 21042502403 is 30420524012.

It is a happy number.

It is not a de Polignac number, because 21042502403 - 2⁴ = 21042502387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21042502423) 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 in 23 ways as a sum of consecutive naturals, for example, 96425 + ... + 226677.

It is an arithmetic number, because the mean of its divisors is an integer number (1026358102).

Almost surely, 2^21042502403 is an apocalyptic number.

21042502403 is a deficient number, since it is larger than the sum of its proper divisors (3590092045).

21042502403 is a wasteful number, since it uses less digits than its factorization.

21042502403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130343 (or 130326 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The spelling of 21042502403 in words is "twenty-one billion, forty-two million, five hundred two thousand, four hundred three".