20516922216491 has 2 divisors, whose sum is σ = 20516922216492. Its totient is φ = 20516922216490.

The previous prime is 20516922216443. The next prime is 20516922216529. The reversal of 20516922216491 is 19461222961502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20516922216491 - 2²² = 20516918022187 is a prime.

It is not a weakly prime, because it can be changed into another prime (20516922416491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10258461108245 + 10258461108246.

It is an arithmetic number, because the mean of its divisors is an integer number (10258461108246).

Almost surely, 2^{20516922216491} is an apocalyptic number.

20516922216491 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516922216491 is an equidigital number, since it uses as much as digits as its factorization.

20516922216491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 933120, while the sum is 50.

The spelling of 20516922216491 in words is "twenty trillion, five hundred sixteen billion, nine hundred twenty-two million, two hundred sixteen thousand, four hundred ninety-one".