1181005491 has 8 divisors (see below), whose sum is σ = 1575351504. Its totient is φ = 786998240.

The previous prime is 1181005489. The next prime is 1181005493. The reversal of 1181005491 is 1945001811.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1181005489) and next prime (1181005493).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1181005491 - 2¹ = 1181005489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1181005493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76440 + ... + 90581.

It is an arithmetic number, because the mean of its divisors is an integer number (196918938).

Almost surely, 2^1181005491 is an apocalyptic number.

1181005491 is a deficient number, since it is larger than the sum of its proper divisors (394346013).

1181005491 is a wasteful number, since it uses less digits than its factorization.

1181005491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169381.

The product of its (nonzero) digits is 1440, while the sum is 30.

The square root of 1181005491 is about 34365.7604455365. The cubic root of 1181005491 is about 1057.0218681433.

The spelling of 1181005491 in words is "one billion, one hundred eighty-one million, five thousand, four hundred ninety-one".