218465629621 has 2 divisors, whose sum is σ = 218465629622. Its totient is φ = 218465629620.

The previous prime is 218465629619. The next prime is 218465629667. The reversal of 218465629621 is 126926564812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162030400900 + 56435228721 = 402530^2 + 237561^2 .

It is a cyclic number.

It is not a de Polignac number, because 218465629621 - 2¹ = 218465629619 is a prime.

Together with 218465629619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218465629691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109232814810 + 109232814811.

It is an arithmetic number, because the mean of its divisors is an integer number (109232814811).

Almost surely, 2^218465629621 is an apocalyptic number.

It is an amenable number.

218465629621 is a deficient number, since it is larger than the sum of its proper divisors (1).

218465629621 is an equidigital number, since it uses as much as digits as its factorization.

218465629621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2488320, while the sum is 52.

The spelling of 218465629621 in words is "two hundred eighteen billion, four hundred sixty-five million, six hundred twenty-nine thousand, six hundred twenty-one".