669421687149 has 24 divisors (see below), whose sum is σ = 973546774200. Its totient is φ = 443233677312.

The previous prime is 669421687111. The next prime is 669421687153. The reversal of 669421687149 is 941786124966.

669421687149 is a `hidden beast` number, since 6 + 6 + 9 + 421 + 68 + 7 + 149 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4691291049 + 664730396100 = 68493^2 + 815310^2 .

It is not a de Polignac number, because 669421687149 - 2⁸ = 669421686893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669421687849) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13751797 + ... + 13800389.

It is an arithmetic number, because the mean of its divisors is an integer number (40564448925).

Almost surely, 2^669421687149 is an apocalyptic number.

669421687149 is the 437337-th nonagonal number.

It is an amenable number.

669421687149 is a deficient number, since it is larger than the sum of its proper divisors (304125087051).

669421687149 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (669421687148) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (59021).

669421687149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59021 (or 59018 counting only the distinct ones).

The product of its digits is 31352832, while the sum is 63.

The spelling of 669421687149 in words is "six hundred sixty-nine billion, four hundred twenty-one million, six hundred eighty-seven thousand, one hundred forty-nine".