20511555043313 has 2 divisors, whose sum is σ = 20511555043314. Its totient is φ = 20511555043312.

The previous prime is 20511555043261. The next prime is 20511555043339. The reversal of 20511555043313 is 31334055511502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14975096634289 + 5536458409024 = 3869767^2 + 2352968^2 .

It is a cyclic number.

It is not a de Polignac number, because 20511555043313 - 2³⁰ = 20510481301489 is a prime.

It is a super-3 number, since 3×20511555043313³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (20511555043013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10255777521656 + 10255777521657.

It is an arithmetic number, because the mean of its divisors is an integer number (10255777521657).

Almost surely, 2^{20511555043313} is an apocalyptic number.

It is an amenable number.

20511555043313 is a deficient number, since it is larger than the sum of its proper divisors (1).

20511555043313 is an equidigital number, since it uses as much as digits as its factorization.

20511555043313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 135000, while the sum is 38.

The spelling of 20511555043313 in words is "twenty trillion, five hundred eleven billion, five hundred fifty-five million, forty-three thousand, three hundred thirteen".