21526466660217 has 10 divisors (see below), whose sum is σ = 32156820566618. Its totient is φ = 14350977773424.

The previous prime is 21526466660183. The next prime is 21526466660243. The reversal of 21526466660217 is 71206666462512.

It can be written as a sum of positive squares in only one way, i.e., 21096282838761 + 430183821456 = 4593069^2 + 655884^2 .

It is not a de Polignac number, because 21526466660217 - 2⁸ = 21526466659961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21526466660717) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 132879423748 + ... + 132879423909.

Almost surely, 2^{21526466660217} is an apocalyptic number.

21526466660217 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21526466660217 is a deficient number, since it is larger than the sum of its proper divisors (10630353906401).

21526466660217 is an equidigital number, since it uses as much as digits as its factorization.

21526466660217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265758847669 (or 265758847660 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 54.

The spelling of 21526466660217 in words is "twenty-one trillion, five hundred twenty-six billion, four hundred sixty-six million, six hundred sixty thousand, two hundred seventeen".