1375541561 has 2 divisors, whose sum is σ = 1375541562. Its totient is φ = 1375541560.

The previous prime is 1375541477. The next prime is 1375541569. The reversal of 1375541561 is 1651455731.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1072955536 + 302586025 = 32756^2 + 17395^2 .

It is a cyclic number.

It is not a de Polignac number, because 1375541561 - 2¹⁸ = 1375279417 is a prime.

It is a super-2 number, since 2×1375541561² = 3784229172076633442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1375541569) 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, 687770780 + 687770781.

It is an arithmetic number, because the mean of its divisors is an integer number (687770781).

Almost surely, 2^1375541561 is an apocalyptic number.

It is an amenable number.

1375541561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1375541561 is an equidigital number, since it uses as much as digits as its factorization.

1375541561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63000, while the sum is 38.

The square root of 1375541561 is about 37088.2941236180. The cubic root of 1375541561 is about 1112.1360165321.

The spelling of 1375541561 in words is "one billion, three hundred seventy-five million, five hundred forty-one thousand, five hundred sixty-one".