1266161643 has 12 divisors (see below), whose sum is σ = 1836019848. Its totient is φ = 840821760.

The previous prime is 1266161641. The next prime is 1266161647. The reversal of 1266161643 is 3461616621.

It is a happy number.

1266161643 is a `hidden beast` number, since 1 + 2 + 6 + 6 + 1 + 6 + 1 + 643 = 666.

It is not a de Polignac number, because 1266161643 - 2¹ = 1266161641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1266161598 and 1266161607.

It is not an unprimeable number, because it can be changed into a prime (1266161641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 271393 + ... + 276018.

It is an arithmetic number, because the mean of its divisors is an integer number (153001654).

Almost surely, 2^1266161643 is an apocalyptic number.

1266161643 is a deficient number, since it is larger than the sum of its proper divisors (569858205).

1266161643 is a wasteful number, since it uses less digits than its factorization.

1266161643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547674 (or 547671 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 1266161643 is about 35583.1651627564. The cubic root of 1266161643 is about 1081.8400397098.

The spelling of 1266161643 in words is "one billion, two hundred sixty-six million, one hundred sixty-one thousand, six hundred forty-three".