1121400018 has 64 divisors (see below), whose sum is σ = 2526733440. Its totient is φ = 368625600.

The previous prime is 1121400017. The next prime is 1121400031. The reversal of 1121400018 is 8100041211.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1121400017) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2432308 + ... + 2432768.

It is an arithmetic number, because the mean of its divisors is an integer number (39480210).

Almost surely, 2^1121400018 is an apocalyptic number.

1121400018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1121400018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1263366720).

1121400018 is an abundant number, since it is smaller than the sum of its proper divisors (1405333422).

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

1121400018 is a wasteful number, since it uses less digits than its factorization.

1121400018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000 (or 994 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The square root of 1121400018 is about 33487.3112984605. The cubic root of 1121400018 is about 1038.9313536010.

Adding to 1121400018 its reverse (8100041211), we get a palindrome (9221441229).

The spelling of 1121400018 in words is "one billion, one hundred twenty-one million, four hundred thousand, eighteen".