1218923988 has 24 divisors (see below), whose sum is σ = 2850009792. Its totient is φ = 405471744.

The previous prime is 1218923983. The next prime is 1218923989. The reversal of 1218923988 is 8893298121.

It is a self number, because there is not a number n which added to its sum of digits gives 1218923988.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218923983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98445 + ... + 110132.

It is an arithmetic number, because the mean of its divisors is an integer number (118750408).

Almost surely, 2^1218923988 is an apocalyptic number.

It is an amenable number.

1218923988 is an abundant number, since it is smaller than the sum of its proper divisors (1631085804).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1218923988 is a wasteful number, since it uses less digits than its factorization.

1218923988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209071 (or 209069 counting only the distinct ones).

The product of its digits is 497664, while the sum is 51.

The square root of 1218923988 is about 34913.0919283870. The cubic root of 1218923988 is about 1068.2154981828.

The spelling of 1218923988 in words is "one billion, two hundred eighteen million, nine hundred twenty-three thousand, nine hundred eighty-eight".