228719781 has 20 divisors (see below), whose sum is σ = 353453100. Its totient is φ = 147220416.

The previous prime is 228719779. The next prime is 228719783. The reversal of 228719781 is 187917822.

It is an interprime number because it is at equal distance from previous prime (228719779) and next prime (228719783).

It can be written as a sum of positive squares in 2 ways, for example, as 194602500 + 34117281 = 13950^2 + 5841^2 .

It is not a de Polignac number, because 228719781 - 2¹ = 228719779 is a prime.

It is a super-2 number, since 2×228719781² = 104625476441375922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228719783) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 46336 + ... + 51033.

It is an arithmetic number, because the mean of its divisors is an integer number (17672655).

Almost surely, 2^228719781 is an apocalyptic number.

It is an amenable number.

228719781 is a deficient number, since it is larger than the sum of its proper divisors (124733319).

228719781 is an equidigital number, since it uses as much as digits as its factorization.

228719781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97410 (or 97401 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 228719781 is about 15123.4844199344. The cubic root of 228719781 is about 611.5536682255.

The spelling of 228719781 in words is "two hundred twenty-eight million, seven hundred nineteen thousand, seven hundred eighty-one".