669721533 has 16 divisors (see below), whose sum is σ = 963896640. Its totient is φ = 411174144.

The previous prime is 669721513. The next prime is 669721537. The reversal of 669721533 is 335127966.

It is not a de Polignac number, because 669721533 - 2⁸ = 669721277 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669721537) 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 15 ways as a sum of consecutive naturals, for example, 2943 + ... + 36716.

It is an arithmetic number, because the mean of its divisors is an integer number (60243540).

Almost surely, 2^669721533 is an apocalyptic number.

It is an amenable number.

669721533 is a deficient number, since it is larger than the sum of its proper divisors (294175107).

669721533 is a wasteful number, since it uses less digits than its factorization.

669721533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40108.

The product of its digits is 204120, while the sum is 42.

The square root of 669721533 is about 25878.9785926725. The cubic root of 669721533 is about 874.9127675758.

The spelling of 669721533 in words is "six hundred sixty-nine million, seven hundred twenty-one thousand, five hundred thirty-three".