1666510641 has 24 divisors (see below), whose sum is σ = 2512449576. Its totient is φ = 1063445760.

The previous prime is 1666510639. The next prime is 1666510711. The reversal of 1666510641 is 1460156661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 66830625 + 1599680016 = 8175^2 + 39996^2 .

It is not a de Polignac number, because 1666510641 - 2¹ = 1666510639 is a prime.

It is a super-3 number, since 3×1666510641³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1666510596 and 1666510605.

It is not an unprimeable number, because it can be changed into a prime (1666510541) by changing a digit.

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 in 23 ways as a sum of consecutive naturals, for example, 23050 + ... + 62163.

It is an arithmetic number, because the mean of its divisors is an integer number (104685399).

Almost surely, 2^1666510641 is an apocalyptic number.

It is an amenable number.

1666510641 is a deficient number, since it is larger than the sum of its proper divisors (845938935).

1666510641 is a wasteful number, since it uses less digits than its factorization.

1666510641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85313 (or 85310 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 1666510641 is about 40822.9180853109. The cubic root of 1666510641 is about 1185.5941025655.

The spelling of 1666510641 in words is "one billion, six hundred sixty-six million, five hundred ten thousand, six hundred forty-one".