66021620057 has 2 divisors, whose sum is σ = 66021620058. Its totient is φ = 66021620056.

The previous prime is 66021620051. The next prime is 66021620099. The reversal of 66021620057 is 75002612066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65714809801 + 306810256 = 256349^2 + 17516^2 .

It is a cyclic number.

It is not a de Polignac number, because 66021620057 - 2³² = 61726652761 is a prime.

It is a super-3 number, since 3×66021620057³ (a number of 33 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66021619999 and 66021620026.

It is not a weakly prime, because it can be changed into another prime (66021620051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33010810028 + 33010810029.

It is an arithmetic number, because the mean of its divisors is an integer number (33010810029).

Almost surely, 2^66021620057 is an apocalyptic number.

It is an amenable number.

66021620057 is a deficient number, since it is larger than the sum of its proper divisors (1).

66021620057 is an equidigital number, since it uses as much as digits as its factorization.

66021620057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 35.

The spelling of 66021620057 in words is "sixty-six billion, twenty-one million, six hundred twenty thousand, fifty-seven".