2178009 has 12 divisors (see below), whose sum is σ = 3262896. Its totient is φ = 1451844.

The previous prime is 2177999. The next prime is 2178037. The reversal of 2178009 is 9008712.

It is not a de Polignac number, because 2178009 - 2⁵ = 2177977 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2178049) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4239 + ... + 4724.

It is an arithmetic number, because the mean of its divisors is an integer number (271908).

2^2178009 is an apocalyptic number.

It is an amenable number.

2178009 is a deficient number, since it is larger than the sum of its proper divisors (1084887).

2178009 is an frugal number, since it uses more digits than its factorization.

2178009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8978 (or 8966 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 2178009 is about 1475.8079143303. The cubic root of 2178009 is about 129.6243395644.

The spelling of 2178009 in words is "two million, one hundred seventy-eight thousand, nine".