669023304721 has 2 divisors, whose sum is σ = 669023304722. Its totient is φ = 669023304720.

The previous prime is 669023304707. The next prime is 669023304727. The reversal of 669023304721 is 127403320966.

669023304721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 632444829696 + 36578475025 = 795264^2 + 191255^2 .

It is a cyclic number.

It is not a de Polignac number, because 669023304721 - 2¹⁵ = 669023271953 is a prime.

It is not a weakly prime, because it can be changed into another prime (669023304727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334511652360 + 334511652361.

It is an arithmetic number, because the mean of its divisors is an integer number (334511652361).

Almost surely, 2^669023304721 is an apocalyptic number.

It is an amenable number.

669023304721 is a deficient number, since it is larger than the sum of its proper divisors (1).

669023304721 is an equidigital number, since it uses as much as digits as its factorization.

669023304721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 326592, while the sum is 43.

The spelling of 669023304721 in words is "six hundred sixty-nine billion, twenty-three million, three hundred four thousand, seven hundred twenty-one".