21260665605607 has 2 divisors, whose sum is σ = 21260665605608. Its totient is φ = 21260665605606.

The previous prime is 21260665605587. The next prime is 21260665605611. The reversal of 21260665605607 is 70650656606212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21260665605607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21260665602607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10630332802803 + 10630332802804.

It is an arithmetic number, because the mean of its divisors is an integer number (10630332802804).

Almost surely, 2^{21260665605607} is an apocalyptic number.

21260665605607 is a deficient number, since it is larger than the sum of its proper divisors (1).

21260665605607 is an equidigital number, since it uses as much as digits as its factorization.

21260665605607 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5443200, while the sum is 52.

The spelling of 21260665605607 in words is "twenty-one trillion, two hundred sixty billion, six hundred sixty-five million, six hundred five thousand, six hundred seven".