66421705 has 12 divisors (see below), whose sum is σ = 92719620. Its totient is φ = 45546144.

The previous prime is 66421661. The next prime is 66421717. The reversal of 66421705 is 50712466.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14235529 + 52186176 = 3773^2 + 7224^2 .

It is not a de Polignac number, because 66421705 - 2¹³ = 66413513 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 135310 + ... + 135799.

It is an arithmetic number, because the mean of its divisors is an integer number (7726635).

Almost surely, 2^66421705 is an apocalyptic number.

It is an amenable number.

66421705 is a deficient number, since it is larger than the sum of its proper divisors (26297915).

66421705 is a wasteful number, since it uses less digits than its factorization.

66421705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271128 (or 271121 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 66421705 is about 8149.9512268479. The cubic root of 66421705 is about 404.9828880643.

The spelling of 66421705 in words is "sixty-six million, four hundred twenty-one thousand, seven hundred five".