66973645 has 4 divisors (see below), whose sum is σ = 80368380. Its totient is φ = 53578912.

The previous prime is 66973607. The next prime is 66973667. The reversal of 66973645 is 54637966.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12376324 + 54597321 = 3518^2 + 7389^2 .

It is a cyclic number.

It is not a de Polignac number, because 66973645 - 2¹⁵ = 66940877 is a prime.

It is a super-3 number, since 3×66973645³ (a number of 24 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66973595 and 66973604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6697360 + ... + 6697369.

It is an arithmetic number, because the mean of its divisors is an integer number (20092095).

Almost surely, 2^66973645 is an apocalyptic number.

It is an amenable number.

66973645 is a deficient number, since it is larger than the sum of its proper divisors (13394735).

66973645 is a wasteful number, since it uses less digits than its factorization.

66973645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13394734.

The product of its digits is 816480, while the sum is 46.

The square root of 66973645 is about 8183.7427256726. The cubic root of 66973645 is about 406.1015482841.

The spelling of 66973645 in words is "sixty-six million, nine hundred seventy-three thousand, six hundred forty-five".