21004240507 has 2 divisors, whose sum is σ = 21004240508. Its totient is φ = 21004240506.

The previous prime is 21004240489. The next prime is 21004240513. The reversal of 21004240507 is 70504240012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21004240507 is a prime.

It is not a weakly prime, because it can be changed into another prime (21004240597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502120253 + 10502120254.

It is an arithmetic number, because the mean of its divisors is an integer number (10502120254).

Almost surely, 2^21004240507 is an apocalyptic number.

21004240507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004240507 is an equidigital number, since it uses as much as digits as its factorization.

21004240507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 25.

Adding to 21004240507 its reverse (70504240012), we get a palindrome (91508480519).

The spelling of 21004240507 in words is "twenty-one billion, four million, two hundred forty thousand, five hundred seven".