21417766061 has 2 divisors, whose sum is σ = 21417766062. Its totient is φ = 21417766060.

The previous prime is 21417766009. The next prime is 21417766109. The reversal of 21417766061 is 16066771412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19744465225 + 1673300836 = 140515^2 + 40906^2 .

It is a cyclic number.

It is not a de Polignac number, because 21417766061 - 2¹⁸ = 21417503917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21417766001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10708883030 + 10708883031.

It is an arithmetic number, because the mean of its divisors is an integer number (10708883031).

Almost surely, 2^21417766061 is an apocalyptic number.

It is an amenable number.

21417766061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21417766061 is an equidigital number, since it uses as much as digits as its factorization.

21417766061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 41.

The spelling of 21417766061 in words is "twenty-one billion, four hundred seventeen million, seven hundred sixty-six thousand, sixty-one".