2178648861 has 8 divisors (see below), whose sum is σ = 2905347264. Its totient is φ = 1452191520.

The previous prime is 2178648859. The next prime is 2178648863. The reversal of 2178648861 is 1688468712.

2178648861 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2178648859) and next prime (2178648863).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2178648861 - 2¹ = 2178648859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178648863) 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, 38001 + ... + 76166.

It is an arithmetic number, because the mean of its divisors is an integer number (363168408).

Almost surely, 2^2178648861 is an apocalyptic number.

It is an amenable number.

2178648861 is a deficient number, since it is larger than the sum of its proper divisors (726698403).

2178648861 is a wasteful number, since it uses less digits than its factorization.

2178648861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120531.

The product of its digits is 1032192, while the sum is 51.

The square root of 2178648861 is about 46675.9987681035. The cubic root of 2178648861 is about 1296.3703211047.

The spelling of 2178648861 in words is "two billion, one hundred seventy-eight million, six hundred forty-eight thousand, eight hundred sixty-one".