66213775 has 12 divisors (see below), whose sum is σ = 83030400. Its totient is φ = 52374080.

The previous prime is 66213769. The next prime is 66213781. The reversal of 66213775 is 57731266.

It is an interprime number because it is at equal distance from previous prime (66213769) and next prime (66213781).

It is not a de Polignac number, because 66213775 - 2⁵ = 66213743 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12655 + ... + 17104.

It is an arithmetic number, because the mean of its divisors is an integer number (6919200).

Almost surely, 2^66213775 is an apocalyptic number.

66213775 is a deficient number, since it is larger than the sum of its proper divisors (16816625).

66213775 is a wasteful number, since it uses less digits than its factorization.

66213775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29858 (or 29853 counting only the distinct ones).

The product of its digits is 52920, while the sum is 37.

The square root of 66213775 is about 8137.1847097138. The cubic root of 66213775 is about 404.5598530796.

The spelling of 66213775 in words is "sixty-six million, two hundred thirteen thousand, seven hundred seventy-five".