1261126754001 has 9 divisors (see below), whose sum is σ = 1821632399899. Its totient is φ = 840748923336.

The previous prime is 1261126753907. The next prime is 1261126754033. The reversal of 1261126754001 is 1004576211621.

The square root of 1261126754001 is 1122999.

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

1261126754001 is a `hidden beast` number, since 1 + 2 + 61 + 126 + 75 + 400 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2969705025 + 1258157048976 = 54495^2 + 1121676^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 1261126754001 - 2¹⁵ = 1261126721233 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1261126750001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3181831 + ... + 3556163.

Almost surely, 2^{1261126754001} is an apocalyptic number.

1261126754001 is the 1122999-th square number.

1261126754001 is the 561500-th centered octagonal number.

It is an amenable number.

1261126754001 is a deficient number, since it is larger than the sum of its proper divisors (560505645898).

1261126754001 is an frugal number, since it uses more digits than its factorization.

1261126754001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 748672 (or 374336 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

Multiplying 1261126754001 by its sum of digits (36), we get a square (45400563144036 = 6737994²).

The spelling of 1261126754001 in words is "one trillion, two hundred sixty-one billion, one hundred twenty-six million, seven hundred fifty-four thousand, one".