118628581 has 2 divisors, whose sum is σ = 118628582. Its totient is φ = 118628580.

The previous prime is 118628579. The next prime is 118628593. The reversal of 118628581 is 185826811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118592100 + 36481 = 10890^2 + 191^2 .

It is a cyclic number.

It is not a de Polignac number, because 118628581 - 2¹ = 118628579 is a prime.

It is a super-2 number, since 2×118628581² = 28145480460147122, which contains 22 as substring.

Together with 118628579, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (118628501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 59314290 + 59314291.

It is an arithmetic number, because the mean of its divisors is an integer number (59314291).

Almost surely, 2^118628581 is an apocalyptic number.

118628581 is the 6889-th centered pentagonal number.

It is an amenable number.

118628581 is a deficient number, since it is larger than the sum of its proper divisors (1).

118628581 is an equidigital number, since it uses as much as digits as its factorization.

118628581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30720, while the sum is 40.

The square root of 118628581 is about 10891.6748482499. The cubic root of 118628581 is about 491.3562053932.

The spelling of 118628581 in words is "one hundred eighteen million, six hundred twenty-eight thousand, five hundred eighty-one".