118355781 has 4 divisors (see below), whose sum is σ = 157807712. Its totient is φ = 78903852.

The previous prime is 118355771. The next prime is 118355789. The reversal of 118355781 is 187553811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 118355781 - 2¹⁸ = 118093637 is a prime.

It is a super-2 number, since 2×118355781² = 28016181792239922, 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 (118355789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19725961 + ... + 19725966.

It is an arithmetic number, because the mean of its divisors is an integer number (39451928).

Almost surely, 2^118355781 is an apocalyptic number.

It is an amenable number.

118355781 is a deficient number, since it is larger than the sum of its proper divisors (39451931).

118355781 is an equidigital number, since it uses as much as digits as its factorization.

118355781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39451930.

The product of its digits is 33600, while the sum is 39.

The square root of 118355781 is about 10879.1443137776. The cubic root of 118355781 is about 490.9792730344.

The spelling of 118355781 in words is "one hundred eighteen million, three hundred fifty-five thousand, seven hundred eighty-one".