669867449 has 2 divisors, whose sum is σ = 669867450. Its totient is φ = 669867448.

The previous prime is 669867421. The next prime is 669867461. The reversal of 669867449 is 944768966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 669153424 + 714025 = 25868^2 + 845^2 .

It is a cyclic number.

It is not a de Polignac number, because 669867449 - 2¹² = 669863353 is a prime.

It is not a weakly prime, because it can be changed into another prime (669867409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334933724 + 334933725.

It is an arithmetic number, because the mean of its divisors is an integer number (334933725).

Almost surely, 2^669867449 is an apocalyptic number.

It is an amenable number.

669867449 is a deficient number, since it is larger than the sum of its proper divisors (1).

669867449 is an equidigital number, since it uses as much as digits as its factorization.

669867449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15676416, while the sum is 59.

The square root of 669867449 is about 25881.7976384949. The cubic root of 669867449 is about 874.9763036848.

It can be divided in two parts, 6698 and 67449, that added together give a palindrome (74147).

The spelling of 669867449 in words is "six hundred sixty-nine million, eight hundred sixty-seven thousand, four hundred forty-nine".