66806442 has 24 divisors (see below), whose sum is σ = 145061280. Its totient is φ = 22220520.

The previous prime is 66806431. The next prime is 66806473. The reversal of 66806442 is 24460866.

It is a happy number.

66806442 is a `hidden beast` number, since 6 + 6 + 8 + 0 + 644 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 66806397 and 66806406.

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, 5059 + ... + 12617.

It is an arithmetic number, because the mean of its divisors is an integer number (6044220).

Almost surely, 2^66806442 is an apocalyptic number.

66806442 is an abundant number, since it is smaller than the sum of its proper divisors (78254838).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66806442 is a wasteful number, since it uses less digits than its factorization.

66806442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8058 (or 8055 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 66806442 is about 8173.5207836036. The cubic root of 66806442 is about 405.7633158243.

The spelling of 66806442 in words is "sixty-six million, eight hundred six thousand, four hundred forty-two".