1978188 has 24 divisors (see below), whose sum is σ = 4887792. Its totient is φ = 620544.

The previous prime is 1978181. The next prime is 1978189. The reversal of 1978188 is 8818791.

It is not an unprimeable number, because it can be changed into a prime (1978181) 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, 4645 + ... + 5052.

It is an arithmetic number, because the mean of its divisors is an integer number (203658).

2^1978188 is an apocalyptic number.

It is an amenable number.

1978188 is an abundant number, since it is smaller than the sum of its proper divisors (2909604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1978188 is a wasteful number, since it uses less digits than its factorization.

1978188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9721 (or 9719 counting only the distinct ones).

The product of its digits is 32256, while the sum is 42.

The square root of 1978188 is about 1406.4807144074. The cubic root of 1978188 is about 125.5324064607.

It can be divided in two parts, 197 and 8188, that added together give a triangular number (8385 = T₁₂₉).

The spelling of 1978188 in words is "one million, nine hundred seventy-eight thousand, one hundred eighty-eight".