228188691481 has 27 divisors (see below), whose sum is σ = 239038611357. Its totient is φ = 217827096000.

The previous prime is 228188691473. The next prime is 228188691499. The reversal of 228188691481 is 184196881822.

The square root of 228188691481 is 477691.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 193152339081 + 35036352400 = 439491^2 + 187180^2 .

It is not a de Polignac number, because 228188691481 - 2³ = 228188691473 is a prime.

It is a super-2 number, since 2×228188691481² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (228188691581) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1194705096 + ... + 1194705286.

Almost surely, 2^228188691481 is an apocalyptic number.

228188691481 is the 477691-st square number.

228188691481 is the 238846-th centered octagonal number.

It is an amenable number.

228188691481 is a deficient number, since it is larger than the sum of its proper divisors (10849919876).

228188691481 is an frugal number, since it uses more digits than its factorization.

228188691481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586 (or 293 counting only the distinct ones).

The product of its digits is 3538944, while the sum is 58.

The spelling of 228188691481 in words is "two hundred twenty-eight billion, one hundred eighty-eight million, six hundred ninety-one thousand, four hundred eighty-one".