1181638 has 4 divisors (see below), whose sum is σ = 1772460. Its totient is φ = 590818.

The previous prime is 1181633. The next prime is 1181647. The reversal of 1181638 is 8361811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8361811 = 23 ⋅363557.

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 as a sum of consecutive naturals, namely, 295408 + ... + 295411.

It is an arithmetic number, because the mean of its divisors is an integer number (443115).

2^1181638 is an apocalyptic number.

1181638 is a deficient number, since it is larger than the sum of its proper divisors (590822).

1181638 is an equidigital number, since it uses as much as digits as its factorization.

1181638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 590821.

The product of its digits is 1152, while the sum is 28.

The square root of 1181638 is about 1087.0317382671. The cubic root of 1181638 is about 105.7210536903.

The spelling of 1181638 in words is "one million, one hundred eighty-one thousand, six hundred thirty-eight".