20515664353 has 2 divisors, whose sum is σ = 20515664354. Its totient is φ = 20515664352.

The previous prime is 20515664317. The next prime is 20515664369. The reversal of 20515664353 is 35346651502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14556905104 + 5958759249 = 120652^2 + 77193^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20515664353 is a prime.

It is not a weakly prime, because it can be changed into another prime (20515662353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10257832176 + 10257832177.

It is an arithmetic number, because the mean of its divisors is an integer number (10257832177).

Almost surely, 2^20515664353 is an apocalyptic number.

It is an amenable number.

20515664353 is a deficient number, since it is larger than the sum of its proper divisors (1).

20515664353 is an equidigital number, since it uses as much as digits as its factorization.

20515664353 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324000, while the sum is 40.

The spelling of 20515664353 in words is "twenty billion, five hundred fifteen million, six hundred sixty-four thousand, three hundred fifty-three".