1666666641 has 16 divisors (see below), whose sum is σ = 2319842304. Its totient is φ = 1062342864.

The previous prime is 1666666637. The next prime is 1666666649. The reversal of 1666666641 is 1466666661.

It is not a de Polignac number, because 1666666641 - 2² = 1666666637 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666666649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235740 + ... + 242706.

It is an arithmetic number, because the mean of its divisors is an integer number (144990144).

Almost surely, 2^1666666641 is an apocalyptic number.

It is an amenable number.

1666666641 is a deficient number, since it is larger than the sum of its proper divisors (653175663).

1666666641 is a wasteful number, since it uses less digits than its factorization.

1666666641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10460.

The product of its digits is 1119744, while the sum is 48.

The square root of 1666666641 is about 40824.8287320351. The cubic root of 1666666641 is about 1185.6310954104.

The spelling of 1666666641 in words is "one billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred forty-one".