669721538343 has 16 divisors (see below), whose sum is σ = 1049074298496. Its totient is φ = 374669391840.

The previous prime is 669721538341. The next prime is 669721538359. The reversal of 669721538343 is 343835127966.

It is not a de Polignac number, because 669721538343 - 2¹ = 669721538341 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669721538341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 780560805 + ... + 780561662.

It is an arithmetic number, because the mean of its divisors is an integer number (65567143656).

Almost surely, 2^669721538343 is an apocalyptic number.

669721538343 is a deficient number, since it is larger than the sum of its proper divisors (379352760153).

669721538343 is a wasteful number, since it uses less digits than its factorization.

669721538343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561122494.

The product of its digits is 19595520, while the sum is 57.

The spelling of 669721538343 in words is "six hundred sixty-nine billion, seven hundred twenty-one million, five hundred thirty-eight thousand, three hundred forty-three".