66420671 has 2 divisors, whose sum is σ = 66420672. Its totient is φ = 66420670.

The previous prime is 66420559. The next prime is 66420677. The reversal of 66420671 is 17602466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66420671 - 2¹⁸ = 66158527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66420677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33210335 + 33210336.

It is an arithmetic number, because the mean of its divisors is an integer number (33210336).

Almost surely, 2^66420671 is an apocalyptic number.

66420671 is a deficient number, since it is larger than the sum of its proper divisors (1).

66420671 is an equidigital number, since it uses as much as digits as its factorization.

66420671 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 66420671 is about 8149.8877906386. The cubic root of 66420671 is about 404.9807865701.

The spelling of 66420671 in words is "sixty-six million, four hundred twenty thousand, six hundred seventy-one".