2656159666 has 4 divisors (see below), whose sum is σ = 3984239502. Its totient is φ = 1328079832.

The previous prime is 2656159657. The next prime is 2656159687. The reversal of 2656159666 is 6669516562.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6669516562 = 2 ⋅3334758281.

It can be written as a sum of positive squares in only one way, i.e., 2114620225 + 541539441 = 45985^2 + 23271^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 664039915 + ... + 664039918.

Almost surely, 2^2656159666 is an apocalyptic number.

2656159666 is a deficient number, since it is larger than the sum of its proper divisors (1328079836).

2656159666 is a wasteful number, since it uses less digits than its factorization.

2656159666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1328079835.

The product of its digits is 3499200, while the sum is 52.

The square root of 2656159666 is about 51537.9439442436. The cubic root of 2656159666 is about 1384.8988645757.

The spelling of 2656159666 in words is "two billion, six hundred fifty-six million, one hundred fifty-nine thousand, six hundred sixty-six".