66785481 has 36 divisors (see below), whose sum is σ = 115278852. Its totient is φ = 37122624.

The previous prime is 66785479. The next prime is 66785483. The reversal of 66785481 is 18458766.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66785479) and next prime (66785483).

It can be written as a sum of positive squares in 2 ways, for example, as 45441081 + 21344400 = 6741^2 + 4620^2 .

It is not a de Polignac number, because 66785481 - 2¹ = 66785479 is a prime.

It is a super-2 number, since 2×66785481² = 8920600944802722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66785483) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 14271 + ... + 18363.

Almost surely, 2^66785481 is an apocalyptic number.

It is an amenable number.

66785481 is a deficient number, since it is larger than the sum of its proper divisors (48493371).

66785481 is a wasteful number, since it uses less digits than its factorization.

66785481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4150 (or 4140 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 66785481 is about 8172.2384326450. The cubic root of 66785481 is about 405.7208743357.

The spelling of 66785481 in words is "sixty-six million, seven hundred eighty-five thousand, four hundred eighty-one".