1903247755561 has 2 divisors, whose sum is σ = 1903247755562. Its totient is φ = 1903247755560.

The previous prime is 1903247755543. The next prime is 1903247755567. The reversal of 1903247755561 is 1655577423091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1901627210025 + 1620545536 = 1378995^2 + 40256^2 .

It is a cyclic number.

It is not a de Polignac number, because 1903247755561 - 2⁵ = 1903247755529 is a prime.

It is not a weakly prime, because it can be changed into another prime (1903247755567) 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, 951623877780 + 951623877781.

It is an arithmetic number, because the mean of its divisors is an integer number (951623877781).

Almost surely, 2^{1903247755561} is an apocalyptic number.

It is an amenable number.

1903247755561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1903247755561 is an equidigital number, since it uses as much as digits as its factorization.

1903247755561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7938000, while the sum is 55.

The spelling of 1903247755561 in words is "one trillion, nine hundred three billion, two hundred forty-seven million, seven hundred fifty-five thousand, five hundred sixty-one".