21003024457 has 2 divisors, whose sum is σ = 21003024458. Its totient is φ = 21003024456.

The previous prime is 21003024443. The next prime is 21003024487. The reversal of 21003024457 is 75442030012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20845873161 + 157151296 = 144381^2 + 12536^2 .

It is a cyclic number.

It is not a de Polignac number, because 21003024457 - 2¹¹ = 21003022409 is a prime.

It is a super-2 number, since 2×21003024457² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21003024487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501512228 + 10501512229.

It is an arithmetic number, because the mean of its divisors is an integer number (10501512229).

Almost surely, 2^21003024457 is an apocalyptic number.

It is an amenable number.

21003024457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003024457 is an equidigital number, since it uses as much as digits as its factorization.

21003024457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6720, while the sum is 28.

Adding to 21003024457 its reverse (75442030012), we get a palindrome (96445054469).

The spelling of 21003024457 in words is "twenty-one billion, three million, twenty-four thousand, four hundred fifty-seven".