669991293 has 6 divisors (see below), whose sum is σ = 967765214. Its totient is φ = 446660856.

The previous prime is 669991271. The next prime is 669991297. The reversal of 669991293 is 392199966.

It can be written as a sum of positive squares in only one way, i.e., 513566244 + 156425049 = 22662^2 + 12507^2 .

It is not a de Polignac number, because 669991293 - 2¹³ = 669983101 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 (669991297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37221730 + ... + 37221747.

Almost surely, 2^669991293 is an apocalyptic number.

It is an amenable number.

669991293 is a deficient number, since it is larger than the sum of its proper divisors (297773921).

669991293 is a wasteful number, since it uses less digits than its factorization.

669991293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74443483 (or 74443480 counting only the distinct ones).

The product of its digits is 1417176, while the sum is 54.

The square root of 669991293 is about 25884.1900201648. The cubic root of 669991293 is about 875.0302217589.

The spelling of 669991293 in words is "six hundred sixty-nine million, nine hundred ninety-one thousand, two hundred ninety-three".