1131220431 has 32 divisors (see below), whose sum is σ = 1907735040. Its totient is φ = 655776000.

The previous prime is 1131220397. The next prime is 1131220457. The reversal of 1131220431 is 1340221311.

1131220431 is a `hidden beast` number, since 1 + 13 + 1 + 220 + 431 = 666.

It is not a de Polignac number, because 1131220431 - 2⁷ = 1131220303 is a prime.

It is a super-2 number, since 2×1131220431² = 2559319327023651522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131220481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 75970 + ... + 89631.

It is an arithmetic number, because the mean of its divisors is an integer number (59616720).

Almost surely, 2^1131220431 is an apocalyptic number.

1131220431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1131220431 is a deficient number, since it is larger than the sum of its proper divisors (776514609).

1131220431 is a wasteful number, since it uses less digits than its factorization.

1131220431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165644 (or 165638 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1131220431 is about 33633.6205455196. The cubic root of 1131220431 is about 1041.9552808740.

Adding to 1131220431 its reverse (1340221311), we get a palindrome (2471441742).

The spelling of 1131220431 in words is "one billion, one hundred thirty-one million, two hundred twenty thousand, four hundred thirty-one".