1266018780625 has 15 divisors (see below), whose sum is σ = 1582052219517. Its totient is φ = 1012792521000.

The previous prime is 1266018780623. The next prime is 1266018780641. The reversal of 1266018780625 is 5260878106621.

It is a happy number.

The square root of 1266018780625 is 1125175.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 99255872401 + 1166762908224 = 315049^2 + 1080168^2 .

It is not a de Polignac number, because 1266018780625 - 2¹ = 1266018780623 is a prime.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1266018780623) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 28106872 + ... + 28151878.

Almost surely, 2^{1266018780625} is an apocalyptic number.

1266018780625 is the 1125175-th square number.

1266018780625 is the 562588-th centered octagonal number.

It is an amenable number.

1266018780625 is a deficient number, since it is larger than the sum of its proper divisors (316033438892).

1266018780625 is an frugal number, since it uses more digits than its factorization.

1266018780625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90034 (or 45012 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 52.

The spelling of 1266018780625 in words is "one trillion, two hundred sixty-six billion, eighteen million, seven hundred eighty thousand, six hundred twenty-five".