2181818738 has 16 divisors (see below), whose sum is σ = 3666743424. Its totient is φ = 964931760.

The previous prime is 2181818699. The next prime is 2181818747. The reversal of 2181818738 is 8378181812.

It is a junction number, because it is equal to n+sod(n) for n = 2181818692 and 2181818701.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1339370 + ... + 1340997.

It is an arithmetic number, because the mean of its divisors is an integer number (229171464).

Almost surely, 2^2181818738 is an apocalyptic number.

2181818738 is a deficient number, since it is larger than the sum of its proper divisors (1484924686).

2181818738 is a wasteful number, since it uses less digits than its factorization.

2181818738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2680417.

The product of its digits is 172032, while the sum is 47.

The square root of 2181818738 is about 46709.9426032617. The cubic root of 2181818738 is about 1296.9987447049.

The spelling of 2181818738 in words is "two billion, one hundred eighty-one million, eight hundred eighteen thousand, seven hundred thirty-eight".