7931666 has 4 divisors (see below), whose sum is σ = 11897502. Its totient is φ = 3965832.

The previous prime is 7931659. The next prime is 7931699. The reversal of 7931666 is 6661397.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6661397 = 491 ⋅13567.

It can be written as a sum of positive squares in only one way, i.e., 4431025 + 3500641 = 2105^2 + 1871^2 .

It is a super-2 number, since 2×7931666² = 125822651071112, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1982915 + ... + 1982918.

Almost surely, 2^7931666 is an apocalyptic number.

7931666 is a deficient number, since it is larger than the sum of its proper divisors (3965836).

7931666 is a wasteful number, since it uses less digits than its factorization.

7931666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3965835.

The product of its digits is 40824, while the sum is 38.

The square root of 7931666 is about 2816.3213595043. The cubic root of 7931666 is about 199.4289208953.

The spelling of 7931666 in words is "seven million, nine hundred thirty-one thousand, six hundred sixty-six".