66907738 has 4 divisors (see below), whose sum is σ = 100361610. Its totient is φ = 33453868.

The previous prime is 66907723. The next prime is 66907739. The reversal of 66907738 is 83770966.

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., 59028489 + 7879249 = 7683^2 + 2807^2 .

It is not an unprimeable number, because it can be changed into a prime (66907739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16726933 + ... + 16726936.

Almost surely, 2^66907738 is an apocalyptic number.

66907738 is a deficient number, since it is larger than the sum of its proper divisors (33453872).

66907738 is a wasteful number, since it uses less digits than its factorization.

66907738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33453871.

The product of its (nonzero) digits is 381024, while the sum is 46.

The square root of 66907738 is about 8179.7150317111. The cubic root of 66907738 is about 405.9682932846.

The spelling of 66907738 in words is "sixty-six million, nine hundred seven thousand, seven hundred thirty-eight".