21003024491 has 2 divisors, whose sum is σ = 21003024492. Its totient is φ = 21003024490.

The previous prime is 21003024487. The next prime is 21003024521. The reversal of 21003024491 is 19442030012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21003024491 - 2² = 21003024487 is a prime.

It is a super-2 number, since 2×21003024491² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21003024491.

It is not a weakly prime, because it can be changed into another prime (21003021491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501512245 + 10501512246.

It is an arithmetic number, because the mean of its divisors is an integer number (10501512246).

Almost surely, 2^21003024491 is an apocalyptic number.

21003024491 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003024491 is an equidigital number, since it uses as much as digits as its factorization.

21003024491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 26.

The spelling of 21003024491 in words is "twenty-one billion, three million, twenty-four thousand, four hundred ninety-one".