1266666981 has 16 divisors (see below), whose sum is σ = 1722003840. Its totient is φ = 827910720.

The previous prime is 1266666979. The next prime is 1266667007. The reversal of 1266666981 is 1896666621.

It is a happy number.

It is not a de Polignac number, because 1266666981 - 2¹ = 1266666979 is a prime.

It is a super-2 number, since 2×1266666981² = 3208890481511308722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266666941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 359016 + ... + 362526.

It is an arithmetic number, because the mean of its divisors is an integer number (107625240).

Almost surely, 2^1266666981 is an apocalyptic number.

It is an amenable number.

1266666981 is a deficient number, since it is larger than the sum of its proper divisors (455336859).

1266666981 is a wasteful number, since it uses less digits than its factorization.

1266666981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5836.

The product of its digits is 1119744, while the sum is 51.

The square root of 1266666981 is about 35590.2652561062. The cubic root of 1266666981 is about 1081.9839450241.

The spelling of 1266666981 in words is "one billion, two hundred sixty-six million, six hundred sixty-six thousand, nine hundred eighty-one".