2118947940 has 72 divisors (see below), whose sum is σ = 6450502968. Its totient is φ = 563028480.

The previous prime is 2118947939. The next prime is 2118947951. The reversal of 2118947940 is 497498112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 760435776 + 1358512164 = 27576^2 + 36858^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29634 + ... + 71526.

It is an arithmetic number, because the mean of its divisors is an integer number (89590319).

Almost surely, 2^2118947940 is an apocalyptic number.

2118947940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2118947940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3225251484).

2118947940 is an abundant number, since it is smaller than the sum of its proper divisors (4331555028).

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

2118947940 is a wasteful number, since it uses less digits than its factorization.

2118947940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42189 (or 42184 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 2118947940 is about 46032.0316736075. The cubic root of 2118947940 is about 1284.4191210446.

The spelling of 2118947940 in words is "two billion, one hundred eighteen million, nine hundred forty-seven thousand, nine hundred forty".