5138807666 has 4 divisors (see below), whose sum is σ = 7708211502. Its totient is φ = 2569403832.

The previous prime is 5138807657. The next prime is 5138807699. The reversal of 5138807666 is 6667088315.

It is a happy number.

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., 5130713641 + 8094025 = 71629^2 + 2845^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1284701915 + ... + 1284701918.

Almost surely, 2^5138807666 is an apocalyptic number.

5138807666 is a deficient number, since it is larger than the sum of its proper divisors (2569403836).

5138807666 is a wasteful number, since it uses less digits than its factorization.

5138807666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2569403835.

The product of its (nonzero) digits is 1451520, while the sum is 50.

The square root of 5138807666 is about 71685.4773716406. The cubic root of 5138807666 is about 1725.6555840149.

The spelling of 5138807666 in words is "five billion, one hundred thirty-eight million, eight hundred seven thousand, six hundred sixty-six".