669638756109 has 4 divisors (see below), whose sum is σ = 892851674816. Its totient is φ = 446425837404.

The previous prime is 669638756089. The next prime is 669638756113. The reversal of 669638756109 is 901657836966.

669638756109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 669638756109 - 2⁵ = 669638756077 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 669638756109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669638756119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111606459349 + ... + 111606459354.

It is an arithmetic number, because the mean of its divisors is an integer number (223212918704).

Almost surely, 2^669638756109 is an apocalyptic number.

It is an amenable number.

669638756109 is a deficient number, since it is larger than the sum of its proper divisors (223212918707).

669638756109 is a wasteful number, since it uses less digits than its factorization.

669638756109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223212918706.

The product of its (nonzero) digits is 88179840, while the sum is 66.

The spelling of 669638756109 in words is "six hundred sixty-nine billion, six hundred thirty-eight million, seven hundred fifty-six thousand, one hundred nine".