2178681705 has 40 divisors (see below), whose sum is σ = 4031495424. Its totient is φ = 1124474400.

The previous prime is 2178681689. The next prime is 2178681719. The reversal of 2178681705 is 5071868712.

It is a happy number.

It is not a de Polignac number, because 2178681705 - 2⁴ = 2178681689 is a prime.

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 39 ways as a sum of consecutive naturals, for example, 74211 + ... + 99320.

Almost surely, 2^2178681705 is an apocalyptic number.

It is an amenable number.

2178681705 is a deficient number, since it is larger than the sum of its proper divisors (1852813719).

2178681705 is a wasteful number, since it uses less digits than its factorization.

2178681705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173579 (or 173570 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 45.

The square root of 2178681705 is about 46676.3505964209. The cubic root of 2178681705 is about 1296.3768355051.

The spelling of 2178681705 in words is "two billion, one hundred seventy-eight million, six hundred eighty-one thousand, seven hundred five".