1261378073225 has 12 divisors (see below), whose sum is σ = 1564132483980. Its totient is φ = 1009087185600.

The previous prime is 1261378073203. The next prime is 1261378073287. The reversal of 1261378073225 is 5223708731621.

It can be written as a sum of positive squares in 6 ways, for example, as 153388155904 + 1107989917321 = 391648^2 + 1052611^2 .

It is not a de Polignac number, because 1261378073225 - 2¹² = 1261378069129 is a prime.

It is a super-2 number, since 2×1261378073225² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1261378073225.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1481231 + ... + 2171819.

It is an arithmetic number, because the mean of its divisors is an integer number (130344373665).

Almost surely, 2^{1261378073225} is an apocalyptic number.

It is an amenable number.

1261378073225 is a deficient number, since it is larger than the sum of its proper divisors (302754410755).

1261378073225 is an equidigital number, since it uses as much as digits as its factorization.

1261378073225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 763660 (or 763655 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 47.

The spelling of 1261378073225 in words is "one trillion, two hundred sixty-one billion, three hundred seventy-eight million, seventy-three thousand, two hundred twenty-five".