66553387 has 2 divisors, whose sum is σ = 66553388. Its totient is φ = 66553386.

The previous prime is 66553381. The next prime is 66553391. The reversal of 66553387 is 78335566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66553387 - 2⁷ = 66553259 is a prime.

It is not a weakly prime, because it can be changed into another prime (66553381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33276693 + 33276694.

It is an arithmetic number, because the mean of its divisors is an integer number (33276694).

Almost surely, 2^66553387 is an apocalyptic number.

66553387 is a deficient number, since it is larger than the sum of its proper divisors (1).

66553387 is an equidigital number, since it uses as much as digits as its factorization.

66553387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 453600, while the sum is 43.

The square root of 66553387 is about 8158.0259254307. The cubic root of 66553387 is about 405.2503395628.

The spelling of 66553387 in words is "sixty-six million, five hundred fifty-three thousand, three hundred eighty-seven".