20511626452991 has 2 divisors, whose sum is σ = 20511626452992. Its totient is φ = 20511626452990.

The previous prime is 20511626452949. The next prime is 20511626453027. The reversal of 20511626452991 is 19925462611502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20511626452991 - 2³⁰ = 20510552711167 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20511626452391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10255813226495 + 10255813226496.

It is an arithmetic number, because the mean of its divisors is an integer number (10255813226496).

Almost surely, 2^{20511626452991} is an apocalyptic number.

20511626452991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20511626452991 is an equidigital number, since it uses as much as digits as its factorization.

20511626452991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2332800, while the sum is 53.

The spelling of 20511626452991 in words is "twenty trillion, five hundred eleven billion, six hundred twenty-six million, four hundred fifty-two thousand, nine hundred ninety-one".