1166555431 has 4 divisors (see below), whose sum is σ = 1169154000. Its totient is φ = 1163956864.

The previous prime is 1166555359. The next prime is 1166555477. The reversal of 1166555431 is 1345556611.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1166555431 is a prime.

It is a super-2 number, since 2×1166555431² = 2721703147191191522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1166555491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1298611 + ... + 1299508.

It is an arithmetic number, because the mean of its divisors is an integer number (292288500).

Almost surely, 2^1166555431 is an apocalyptic number.

1166555431 is a deficient number, since it is larger than the sum of its proper divisors (2598569).

1166555431 is an equidigital number, since it uses as much as digits as its factorization.

1166555431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2598568.

The product of its digits is 54000, while the sum is 37.

The square root of 1166555431 is about 34154.8741909555. The cubic root of 1166555431 is about 1052.6931411903.

The spelling of 1166555431 in words is "one billion, one hundred sixty-six million, five hundred fifty-five thousand, four hundred thirty-one".