20618956133 has 2 divisors, whose sum is σ = 20618956134. Its totient is φ = 20618956132.

The previous prime is 20618956103. The next prime is 20618956151. The reversal of 20618956133 is 33165981602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10338415684 + 10280540449 = 101678^2 + 101393^2 .

It is a cyclic number.

It is not a de Polignac number, because 20618956133 - 2¹⁸ = 20618693989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20618956103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10309478066 + 10309478067.

It is an arithmetic number, because the mean of its divisors is an integer number (10309478067).

Almost surely, 2^20618956133 is an apocalyptic number.

It is an amenable number.

20618956133 is a deficient number, since it is larger than the sum of its proper divisors (1).

20618956133 is an equidigital number, since it uses as much as digits as its factorization.

20618956133 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 20618956133 in words is "twenty billion, six hundred eighteen million, nine hundred fifty-six thousand, one hundred thirty-three".