66772945 has 4 divisors (see below), whose sum is σ = 80127540. Its totient is φ = 53418352.

The previous prime is 66772939. The next prime is 66772949. The reversal of 66772945 is 54927766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54927766 = 2 ⋅27463883.

It can be written as a sum of positive squares in 2 ways, for example, as 42211009 + 24561936 = 6497^2 + 4956^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66772945 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66772895 and 66772904.

It is not an unprimeable number, because it can be changed into a prime (66772949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6677290 + ... + 6677299.

It is an arithmetic number, because the mean of its divisors is an integer number (20031885).

Almost surely, 2^66772945 is an apocalyptic number.

It is an amenable number.

66772945 is a deficient number, since it is larger than the sum of its proper divisors (13354595).

66772945 is a wasteful number, since it uses less digits than its factorization.

66772945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13354594.

The product of its digits is 635040, while the sum is 46.

The square root of 66772945 is about 8171.4714097279. The cubic root of 66772945 is about 405.6954874049.

The spelling of 66772945 in words is "sixty-six million, seven hundred seventy-two thousand, nine hundred forty-five".