1266721125 has 16 divisors (see below), whose sum is σ = 2107824576. Its totient is φ = 675584400.

The previous prime is 1266721123. The next prime is 1266721139. The reversal of 1266721125 is 5211276621.

It is not a de Polignac number, because 1266721125 - 2¹ = 1266721123 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266721121) 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, 1688587 + ... + 1689336.

It is an arithmetic number, because the mean of its divisors is an integer number (131739036).

Almost surely, 2^1266721125 is an apocalyptic number.

1266721125 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1266721125 is a deficient number, since it is larger than the sum of its proper divisors (841103451).

1266721125 is an equidigital number, since it uses as much as digits as its factorization.

1266721125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3377941 (or 3377931 counting only the distinct ones).

The product of its digits is 10080, while the sum is 33.

The square root of 1266721125 is about 35591.0259054161. The cubic root of 1266721125 is about 1081.9993613635. Note that the first 3 decimals are identical.

Adding to 1266721125 its reverse (5211276621), we get a palindrome (6477997746).

The spelling of 1266721125 in words is "one billion, two hundred sixty-six million, seven hundred twenty-one thousand, one hundred twenty-five".