1266402889 has 4 divisors (see below), whose sum is σ = 1272964756. Its totient is φ = 1259841024.

The previous prime is 1266402871. The next prime is 1266402899. The reversal of 1266402889 is 9882046621.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 327899664 + 938503225 = 18108^2 + 30635^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266402889 - 2²⁵ = 1232848457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1266402859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3280644 + ... + 3281029.

It is an arithmetic number, because the mean of its divisors is an integer number (318241189).

Almost surely, 2^1266402889 is an apocalyptic number.

It is an amenable number.

1266402889 is a deficient number, since it is larger than the sum of its proper divisors (6561867).

1266402889 is an equidigital number, since it uses as much as digits as its factorization.

1266402889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6561866.

The product of its (nonzero) digits is 331776, while the sum is 46.

The square root of 1266402889 is about 35586.5548908573. The cubic root of 1266402889 is about 1081.9087442099.

The spelling of 1266402889 in words is "one billion, two hundred sixty-six million, four hundred two thousand, eight hundred eighty-nine".