1181631 has 16 divisors (see below), whose sum is σ = 1749888. Its totient is φ = 703200.

The previous prime is 1181617. The next prime is 1181633. The reversal of 1181631 is 1361811.

1181631 = T₄₅₈ + T₄₅₉ + ... + T₄₆₈.

It is not a de Polignac number, because 1181631 - 2¹¹ = 1179583 is a prime.

It is a super-2 number, since 2×1181631² = 2792503640322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1181598 and 1181607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1181633) 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, 1720 + ... + 2306.

It is an arithmetic number, because the mean of its divisors is an integer number (109368).

2^1181631 is an apocalyptic number.

1181631 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1181631 is a deficient number, since it is larger than the sum of its proper divisors (568257).

1181631 is a wasteful number, since it uses less digits than its factorization.

1181631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662.

The product of its digits is 144, while the sum is 21.

The square root of 1181631 is about 1087.0285184851. The cubic root of 1181631 is about 105.7208449268.

The spelling of 1181631 in words is "one million, one hundred eighty-one thousand, six hundred thirty-one".