1266244561 has 8 divisors (see below), whose sum is σ = 1270080000. Its totient is φ = 1262416320.

The previous prime is 1266244543. The next prime is 1266244589. The reversal of 1266244561 is 1654426621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1266244561 - 2¹¹ = 1266242513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1266244561.

It is not an unprimeable number, because it can be changed into a prime (1266242561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 632440 + ... + 634438.

It is an arithmetic number, because the mean of its divisors is an integer number (158760000).

Almost surely, 2^1266244561 is an apocalyptic number.

It is an amenable number.

1266244561 is a deficient number, since it is larger than the sum of its proper divisors (3835439).

1266244561 is an equidigital number, since it uses as much as digits as its factorization.

1266244561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3599.

The product of its digits is 69120, while the sum is 37.

The square root of 1266244561 is about 35584.3302733099. The cubic root of 1266244561 is about 1081.8636549290.

The spelling of 1266244561 in words is "one billion, two hundred sixty-six million, two hundred forty-four thousand, five hundred sixty-one".