1181991455 has 16 divisors (see below), whose sum is σ = 1460978400. Its totient is φ = 917350272.

The previous prime is 1181991451. The next prime is 1181991491. The reversal of 1181991455 is 5541991811.

It is a cyclic number.

It is not a de Polignac number, because 1181991455 - 2² = 1181991451 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1181991451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55412 + ... + 73718.

It is an arithmetic number, because the mean of its divisors is an integer number (91311150).

Almost surely, 2^1181991455 is an apocalyptic number.

1181991455 is a deficient number, since it is larger than the sum of its proper divisors (278986945).

1181991455 is a wasteful number, since it uses less digits than its factorization.

1181991455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18698.

The product of its digits is 64800, while the sum is 44.

The square root of 1181991455 is about 34380.1026031046. The cubic root of 1181991455 is about 1057.3159383595.

The spelling of 1181991455 in words is "one billion, one hundred eighty-one million, nine hundred ninety-one thousand, four hundred fifty-five".