229918781 has 4 divisors (see below), whose sum is σ = 229985052. Its totient is φ = 229852512.

The previous prime is 229918769. The next prime is 229918789. The reversal of 229918781 is 187819922.

229918781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187819922 = 2 ⋅93909961.

It can be written as a sum of positive squares in 2 ways, for example, as 76282756 + 153636025 = 8734^2 + 12395^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-229918781 is a prime.

It is a super-2 number, since 2×229918781² = 105725291713051922, 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 (229918789) 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, 27626 + ... + 34971.

It is an arithmetic number, because the mean of its divisors is an integer number (57496263).

Almost surely, 2^229918781 is an apocalyptic number.

It is an amenable number.

229918781 is a deficient number, since it is larger than the sum of its proper divisors (66271).

229918781 is an equidigital number, since it uses as much as digits as its factorization.

229918781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66270.

The product of its digits is 145152, while the sum is 47.

The square root of 229918781 is about 15163.0729405355. The cubic root of 229918781 is about 612.6204397892.

The spelling of 229918781 in words is "two hundred twenty-nine million, nine hundred eighteen thousand, seven hundred eighty-one".