1155135521 has 2 divisors, whose sum is σ = 1155135522. Its totient is φ = 1155135520.

The previous prime is 1155135503. The next prime is 1155135557. The reversal of 1155135521 is 1255315511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1055535121 + 99600400 = 32489^2 + 9980^2 .

It is an emirp because it is prime and its reverse (1255315511) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1155135521 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1155635521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 577567760 + 577567761.

It is an arithmetic number, because the mean of its divisors is an integer number (577567761).

Almost surely, 2^1155135521 is an apocalyptic number.

It is an amenable number.

1155135521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1155135521 is an equidigital number, since it uses as much as digits as its factorization.

1155135521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3750, while the sum is 29.

The square root of 1155135521 is about 33987.2846958977. The cubic root of 1155135521 is about 1049.2467828628.

The spelling of 1155135521 in words is "one billion, one hundred fifty-five million, one hundred thirty-five thousand, five hundred twenty-one".