1218722132 has 18 divisors (see below), whose sum is σ = 2191973742. Its totient is φ = 592889184.

The previous prime is 1218722081. The next prime is 1218722143. The reversal of 1218722132 is 2312278121.

It can be written as a sum of positive squares in 3 ways, for example, as 257474116 + 961248016 = 16046^2 + 31004^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1218722095 and 1218722104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105803 + ... + 116754.

It is an arithmetic number, because the mean of its divisors is an integer number (121776319).

Almost surely, 2^1218722132 is an apocalyptic number.

It is an amenable number.

1218722132 is a deficient number, since it is larger than the sum of its proper divisors (973251610).

1218722132 is a wasteful number, since it uses less digits than its factorization.

1218722132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222635 (or 222596 counting only the distinct ones).

The product of its digits is 2688, while the sum is 29.

The square root of 1218722132 is about 34910.2009733545. The cubic root of 1218722132 is about 1068.1565287930.

The spelling of 1218722132 in words is "one billion, two hundred eighteen million, seven hundred twenty-two thousand, one hundred thirty-two".