66088021 has 2 divisors, whose sum is σ = 66088022. Its totient is φ = 66088020.

The previous prime is 66087991. The next prime is 66088067. The reversal of 66088021 is 12088066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65431921 + 656100 = 8089^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 66088021 - 2⁷ = 66087893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66088091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33044010 + 33044011.

It is an arithmetic number, because the mean of its divisors is an integer number (33044011).

Almost surely, 2^66088021 is an apocalyptic number.

It is an amenable number.

66088021 is a deficient number, since it is larger than the sum of its proper divisors (1).

66088021 is an equidigital number, since it uses as much as digits as its factorization.

66088021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 66088021 is about 8129.4539176995. The cubic root of 66088021 is about 404.3035757855.

The spelling of 66088021 in words is "sixty-six million, eighty-eight thousand, twenty-one".