66977738 has 4 divisors (see below), whose sum is σ = 100466610. Its totient is φ = 33488868.

The previous prime is 66977731. The next prime is 66977753. The reversal of 66977738 is 83777966.

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

It can be written as a sum of positive squares in only one way, i.e., 65496649 + 1481089 = 8093^2 + 1217^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66977738.

It is not an unprimeable number, because it can be changed into a prime (66977731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16744433 + ... + 16744436.

Almost surely, 2^66977738 is an apocalyptic number.

66977738 is a deficient number, since it is larger than the sum of its proper divisors (33488872).

66977738 is a wasteful number, since it uses less digits than its factorization.

66977738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33488871.

The product of its digits is 2667168, while the sum is 53.

The square root of 66977738 is about 8183.9927908082. The cubic root of 66977738 is about 406.1098208903.

The spelling of 66977738 in words is "sixty-six million, nine hundred seventy-seven thousand, seven hundred thirty-eight".