21417812260987 has 2 divisors, whose sum is σ = 21417812260988. Its totient is φ = 21417812260986.

The previous prime is 21417812260931. The next prime is 21417812261009. The reversal of 21417812260987 is 78906221871412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21417812260987 is a prime.

It is not a weakly prime, because it can be changed into another prime (21417812260927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10708906130493 + 10708906130494.

It is an arithmetic number, because the mean of its divisors is an integer number (10708906130494).

Almost surely, 2^{21417812260987} is an apocalyptic number.

21417812260987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21417812260987 is an equidigital number, since it uses as much as digits as its factorization.

21417812260987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5419008, while the sum is 58.

The spelling of 21417812260987 in words is "twenty-one trillion, four hundred seventeen billion, eight hundred twelve million, two hundred sixty thousand, nine hundred eighty-seven".