1266665898 has 16 divisors (see below), whose sum is σ = 2540636640. Its totient is φ = 421004496.

The previous prime is 1266665891. The next prime is 1266665899. The reversal of 1266665898 is 8985666621.

It is a happy number.

It is a super-2 number, since 2×1266665898² = 3208884994312292808, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1266665891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 302113 + ... + 306276.

It is an arithmetic number, because the mean of its divisors is an integer number (158789790).

Almost surely, 2^1266665898 is an apocalyptic number.

1266665898 is an abundant number, since it is smaller than the sum of its proper divisors (1273970742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1266665898 is a wasteful number, since it uses less digits than its factorization.

1266665898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608741.

The product of its digits is 7464960, while the sum is 57.

The square root of 1266665898 is about 35590.2500412683. The cubic root of 1266665898 is about 1081.9836366587.

The spelling of 1266665898 in words is "one billion, two hundred sixty-six million, six hundred sixty-five thousand, eight hundred ninety-eight".