669573591581 has 8 divisors (see below), whose sum is σ = 670431772920. Its totient is φ = 668715533568.

The previous prime is 669573591571. The next prime is 669573591649. The reversal of 669573591581 is 185195375966.

It can be written as a sum of positive squares in 4 ways, for example, as 219244015225 + 450329576356 = 468235^2 + 671066^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-669573591581 is a prime.

It is a super-2 number, since 2×669573591581² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669573591541) 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, 16208705 + ... + 16249961.

It is an arithmetic number, because the mean of its divisors is an integer number (83803971615).

Almost surely, 2^669573591581 is an apocalyptic number.

It is an amenable number.

669573591581 is a deficient number, since it is larger than the sum of its proper divisors (858181339).

669573591581 is a wasteful number, since it uses less digits than its factorization.

669573591581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61663.

The product of its digits is 61236000, while the sum is 65.

The spelling of 669573591581 in words is "six hundred sixty-nine billion, five hundred seventy-three million, five hundred ninety-one thousand, five hundred eighty-one".