1261503774737 has 2 divisors, whose sum is σ = 1261503774738. Its totient is φ = 1261503774736.

The previous prime is 1261503774673. The next prime is 1261503774779. The reversal of 1261503774737 is 7374773051621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1240797715921 + 20706058816 = 1113911^2 + 143896^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261503774737 - 2⁶ = 1261503774673 is a prime.

It is not a weakly prime, because it can be changed into another prime (261503774737) 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 as a sum of consecutive naturals, namely, 630751887368 + 630751887369.

It is an arithmetic number, because the mean of its divisors is an integer number (630751887369).

Almost surely, 2^{1261503774737} is an apocalyptic number.

It is an amenable number.

1261503774737 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261503774737 is an equidigital number, since it uses as much as digits as its factorization.

1261503774737 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5186160, while the sum is 53.

The spelling of 1261503774737 in words is "one trillion, two hundred sixty-one billion, five hundred three million, seven hundred seventy-four thousand, seven hundred thirty-seven".