1666213753 has 8 divisors (see below), whose sum is σ = 1673023176. Its totient is φ = 1659417600.

The previous prime is 1666213739. The next prime is 1666213789. The reversal of 1666213753 is 3573126661.

It can be written as a sum of positive squares in 4 ways, for example, as 270668304 + 1395545449 = 16452^2 + 37357^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1666213753 - 2¹³ = 1666205561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666213733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 303513 + ... + 308953.

It is an arithmetic number, because the mean of its divisors is an integer number (209127897).

Almost surely, 2^1666213753 is an apocalyptic number.

It is an amenable number.

1666213753 is a deficient number, since it is larger than the sum of its proper divisors (6809423).

1666213753 is an equidigital number, since it uses as much as digits as its factorization.

1666213753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6635.

The product of its digits is 136080, while the sum is 40.

The square root of 1666213753 is about 40819.2816325814. The cubic root of 1666213753 is about 1185.5236940609.

The spelling of 1666213753 in words is "one billion, six hundred sixty-six million, two hundred thirteen thousand, seven hundred fifty-three".