2164378 has 4 divisors (see below), whose sum is σ = 3246570. Its totient is φ = 1082188.

The previous prime is 2164367. The next prime is 2164387. The reversal of 2164378 is 8734612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2053489 + 110889 = 1433^2 + 333^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 541093 + ... + 541096.

2^2164378 is an apocalyptic number.

2164378 is a deficient number, since it is larger than the sum of its proper divisors (1082192).

2164378 is a wasteful number, since it uses less digits than its factorization.

2164378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082191.

The product of its digits is 8064, while the sum is 31.

The square root of 2164378 is about 1471.1825175688. The cubic root of 2164378 is about 129.3533568625.

The spelling of 2164378 in words is "two million, one hundred sixty-four thousand, three hundred seventy-eight".