1668337021 has 8 divisors (see below), whose sum is σ = 1830570840. Its totient is φ = 1510946112.

The previous prime is 1668336991. The next prime is 1668337049. The reversal of 1668337021 is 1207338661.

It can be written as a sum of positive squares in 4 ways, for example, as 638825625 + 1029511396 = 25275^2 + 32086^2 .

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

It is not a de Polignac number, because 1668337021 - 2¹⁹ = 1667812733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668337061) 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, 1210006 + ... + 1211383.

It is an arithmetic number, because the mean of its divisors is an integer number (228821355).

Almost surely, 2^1668337021 is an apocalyptic number.

It is an amenable number.

1668337021 is a deficient number, since it is larger than the sum of its proper divisors (162233819).

1668337021 is a wasteful number, since it uses less digits than its factorization.

1668337021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2421455.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 1668337021 is about 40845.2815022739. The cubic root of 1668337021 is about 1186.0270540595.

The spelling of 1668337021 in words is "one billion, six hundred sixty-eight million, three hundred thirty-seven thousand, twenty-one".