20645646353 has 2 divisors, whose sum is σ = 20645646354. Its totient is φ = 20645646352.

The previous prime is 20645646323. The next prime is 20645646367. The reversal of 20645646353 is 35364654602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18997935889 + 1647710464 = 137833^2 + 40592^2 .

It is a cyclic number.

It is not a de Polignac number, because 20645646353 - 2¹² = 20645642257 is a prime.

It is not a weakly prime, because it can be changed into another prime (20645646313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322823176 + 10322823177.

It is an arithmetic number, because the mean of its divisors is an integer number (10322823177).

Almost surely, 2^20645646353 is an apocalyptic number.

It is an amenable number.

20645646353 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645646353 is an equidigital number, since it uses as much as digits as its factorization.

20645646353 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1555200, while the sum is 44.

The spelling of 20645646353 in words is "twenty billion, six hundred forty-five million, six hundred forty-six thousand, three hundred fifty-three".