1218388 has 6 divisors (see below), whose sum is σ = 2132186. Its totient is φ = 609192.

The previous prime is 1218383. The next prime is 1218391. The reversal of 1218388 is 8838121.

It can be written as a sum of positive squares in only one way, i.e., 1056784 + 161604 = 1028^2 + 402^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 152295 + ... + 152302.

2^1218388 is an apocalyptic number.

It is an amenable number.

1218388 is a deficient number, since it is larger than the sum of its proper divisors (913798).

1218388 is a wasteful number, since it uses less digits than its factorization.

1218388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304601 (or 304599 counting only the distinct ones).

The product of its digits is 3072, while the sum is 31.

The square root of 1218388 is about 1103.8061424000. The cubic root of 1218388 is about 106.8058902520.

The spelling of 1218388 in words is "one million, two hundred eighteen thousand, three hundred eighty-eight".