66420553 has 2 divisors, whose sum is σ = 66420554. Its totient is φ = 66420552.

The previous prime is 66420539. The next prime is 66420559. The reversal of 66420553 is 35502466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48553024 + 17867529 = 6968^2 + 4227^2 .

It is a cyclic number.

It is not a de Polignac number, because 66420553 - 2²⁵ = 32866121 is a prime.

It is not a weakly prime, because it can be changed into another prime (66420559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33210276 + 33210277.

It is an arithmetic number, because the mean of its divisors is an integer number (33210277).

Almost surely, 2^66420553 is an apocalyptic number.

It is an amenable number.

66420553 is a deficient number, since it is larger than the sum of its proper divisors (1).

66420553 is an equidigital number, since it uses as much as digits as its factorization.

66420553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 66420553 is about 8149.8805512719. The cubic root of 66420553 is about 404.9805467464.

The spelling of 66420553 in words is "sixty-six million, four hundred twenty thousand, five hundred fifty-three".