1155505381 has 2 divisors, whose sum is σ = 1155505382. Its totient is φ = 1155505380.

The previous prime is 1155505369. The next prime is 1155505411. The reversal of 1155505381 is 1835055511.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 605602881 + 549902500 = 24609^2 + 23450^2 .

It is a cyclic number.

It is not a de Polignac number, because 1155505381 - 2⁹ = 1155504869 is a prime.

It is a super-2 number, since 2×1155505381² = 2670385371039910322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1155505321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 577752690 + 577752691.

It is an arithmetic number, because the mean of its divisors is an integer number (577752691).

Almost surely, 2^1155505381 is an apocalyptic number.

It is an amenable number.

1155505381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1155505381 is an equidigital number, since it uses as much as digits as its factorization.

1155505381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15000, while the sum is 34.

The square root of 1155505381 is about 33992.7254129468. The cubic root of 1155505381 is about 1049.3587561613.

The spelling of 1155505381 in words is "one billion, one hundred fifty-five million, five hundred five thousand, three hundred eighty-one".