66816582 has 32 divisors (see below), whose sum is σ = 156279552. Its totient is φ = 18645984.

The previous prime is 66816569. The next prime is 66816601. The reversal of 66816582 is 28561866.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16693 + ... + 20304.

It is an arithmetic number, because the mean of its divisors is an integer number (4883736).

Almost surely, 2^66816582 is an apocalyptic number.

66816582 is an abundant number, since it is smaller than the sum of its proper divisors (89462970).

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

66816582 is a wasteful number, since it uses less digits than its factorization.

66816582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37052.

The product of its digits is 138240, while the sum is 42.

The square root of 66816582 is about 8174.1410557930. The cubic root of 66816582 is about 405.7838439438.

The spelling of 66816582 in words is "sixty-six million, eight hundred sixteen thousand, five hundred eighty-two".