20511409843 has 2 divisors, whose sum is σ = 20511409844. Its totient is φ = 20511409842.

The previous prime is 20511409819. The next prime is 20511409859. The reversal of 20511409843 is 34890411502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20511409843 - 2¹⁷ = 20511278771 is a prime.

It is not a weakly prime, because it can be changed into another prime (20511409343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10255704921 + 10255704922.

It is an arithmetic number, because the mean of its divisors is an integer number (10255704922).

Almost surely, 2^20511409843 is an apocalyptic number.

20511409843 is a deficient number, since it is larger than the sum of its proper divisors (1).

20511409843 is an equidigital number, since it uses as much as digits as its factorization.

20511409843 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 37.

The spelling of 20511409843 in words is "twenty billion, five hundred eleven million, four hundred nine thousand, eight hundred forty-three".