506111666 has 4 divisors (see below), whose sum is σ = 759167502. Its totient is φ = 253055832.

The previous prime is 506111647. The next prime is 506111687. The reversal of 506111666 is 666111605.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666111605 = 5 ⋅133222321.

It can be written as a sum of positive squares in only one way, i.e., 365001025 + 141110641 = 19105^2 + 11879^2 .

It is a super-2 number, since 2×506111666² = 512298036922591112, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126527915 + ... + 126527918.

Almost surely, 2^506111666 is an apocalyptic number.

506111666 is a deficient number, since it is larger than the sum of its proper divisors (253055836).

506111666 is a wasteful number, since it uses less digits than its factorization.

506111666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253055835.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 506111666 is about 22496.9257010819. The cubic root of 506111666 is about 796.9213267872.

The spelling of 506111666 in words is "five hundred six million, one hundred eleven thousand, six hundred sixty-six".