21040326617 has 2 divisors, whose sum is σ = 21040326618. Its totient is φ = 21040326616.

The previous prime is 21040326547. The next prime is 21040326661. The reversal of 21040326617 is 71662304012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21029640256 + 10686361 = 145016^2 + 3269^2 .

It is a cyclic number.

It is not a de Polignac number, because 21040326617 - 2¹² = 21040322521 is a prime.

It is not a weakly prime, because it can be changed into another prime (21040326667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520163308 + 10520163309.

It is an arithmetic number, because the mean of its divisors is an integer number (10520163309).

Almost surely, 2^21040326617 is an apocalyptic number.

It is an amenable number.

21040326617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040326617 is an equidigital number, since it uses as much as digits as its factorization.

21040326617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

The spelling of 21040326617 in words is "twenty-one billion, forty million, three hundred twenty-six thousand, six hundred seventeen".