66243775 has 18 divisors (see below), whose sum is σ = 88952640. Its totient is φ = 48915360.

The previous prime is 66243767. The next prime is 66243797. The reversal of 66243775 is 57734266.

It is not a de Polignac number, because 66243775 - 2³ = 66243767 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3615 + ... + 12064.

Almost surely, 2^66243775 is an apocalyptic number.

66243775 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66243775 is a deficient number, since it is larger than the sum of its proper divisors (22708865).

66243775 is a wasteful number, since it uses less digits than its factorization.

66243775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15715 (or 15697 counting only the distinct ones).

The product of its digits is 211680, while the sum is 40.

The square root of 66243775 is about 8139.0278903564. The cubic root of 66243775 is about 404.6209429011.

The spelling of 66243775 in words is "sixty-six million, two hundred forty-three thousand, seven hundred seventy-five".