2178318021 has 16 divisors (see below), whose sum is σ = 3197536320. Its totient is φ = 1308078720.

The previous prime is 2178318011. The next prime is 2178318053. The reversal of 2178318021 is 1208138712.

It is not a de Polignac number, because 2178318021 - 2⁵ = 2178317989 is a prime.

It is a super-2 number, since 2×2178318021² = 9490138801226712882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178318011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 299200 + ... + 306393.

It is an arithmetic number, because the mean of its divisors is an integer number (199846020).

Almost surely, 2^2178318021 is an apocalyptic number.

It is an amenable number.

2178318021 is a deficient number, since it is larger than the sum of its proper divisors (1019218299).

2178318021 is a wasteful number, since it uses less digits than its factorization.

2178318021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605716.

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 2178318021 is about 46672.4546279709. The cubic root of 2178318021 is about 1296.3046974244.

The spelling of 2178318021 in words is "two billion, one hundred seventy-eight million, three hundred eighteen thousand, twenty-one".