20218333550621 has 2 divisors, whose sum is σ = 20218333550622. Its totient is φ = 20218333550620.

The previous prime is 20218333550549. The next prime is 20218333550627. The reversal of 20218333550621 is 12605533381202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19809718557721 + 408614992900 = 4450811^2 + 639230^2 .

It is a cyclic number.

It is not a de Polignac number, because 20218333550621 - 2³⁰ = 20217259808797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20218333550627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10109166775310 + 10109166775311.

It is an arithmetic number, because the mean of its divisors is an integer number (10109166775311).

Almost surely, 2^{20218333550621} is an apocalyptic number.

It is an amenable number.

20218333550621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20218333550621 is an equidigital number, since it uses as much as digits as its factorization.

20218333550621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 20218333550621 in words is "twenty trillion, two hundred eighteen billion, three hundred thirty-three million, five hundred fifty thousand, six hundred twenty-one".