21606251526611 has 2 divisors, whose sum is σ = 21606251526612. Its totient is φ = 21606251526610.

The previous prime is 21606251526577. The next prime is 21606251526641. The reversal of 21606251526611 is 11662515260612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21606251526611 - 2¹⁰ = 21606251525587 is a prime.

It is a super-2 number, since 2×21606251526611² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21606251526641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10803125763305 + 10803125763306.

It is an arithmetic number, because the mean of its divisors is an integer number (10803125763306).

Almost surely, 2^{21606251526611} is an apocalyptic number.

21606251526611 is a deficient number, since it is larger than the sum of its proper divisors (1).

21606251526611 is an equidigital number, since it uses as much as digits as its factorization.

21606251526611 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 259200, while the sum is 44.

The spelling of 21606251526611 in words is "twenty-one trillion, six hundred six billion, two hundred fifty-one million, five hundred twenty-six thousand, six hundred eleven".