1666001656 has 16 divisors (see below), whose sum is σ = 3407730840. Its totient is φ = 757273440.

The previous prime is 1666001653. The next prime is 1666001713. The reversal of 1666001656 is 6561006661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666001653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9465831 + ... + 9466006.

Almost surely, 2^1666001656 is an apocalyptic number.

It is an amenable number.

1666001656 is an abundant number, since it is smaller than the sum of its proper divisors (1741729184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1666001656 is a wasteful number, since it uses less digits than its factorization.

1666001656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18931854 (or 18931850 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 1666001656 is about 40816.6835497447. The cubic root of 1666001656 is about 1185.4733890529.

The spelling of 1666001656 in words is "one billion, six hundred sixty-six million, one thousand, six hundred fifty-six".