2173978 has 4 divisors (see below), whose sum is σ = 3260970. Its totient is φ = 1086988.

The previous prime is 2173967. The next prime is 2173981. The reversal of 2173978 is 8793712.

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., 1159929 + 1014049 = 1077^2 + 1007^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 543493 + ... + 543496.

2^2173978 is an apocalyptic number.

2173978 is a deficient number, since it is larger than the sum of its proper divisors (1086992).

2173978 is a wasteful number, since it uses less digits than its factorization.

2173978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086991.

The product of its digits is 21168, while the sum is 37.

The square root of 2173978 is about 1474.4415892127. The cubic root of 2173978 is about 129.5443217749.

The spelling of 2173978 in words is "two million, one hundred seventy-three thousand, nine hundred seventy-eight".