1986978 has 16 divisors (see below), whose sum is σ = 4541760. Its totient is φ = 567696.

The previous prime is 1986967. The next prime is 1986989. The reversal of 1986978 is 8796891.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1986967) and next prime (1986989).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23613 + ... + 23696.

It is an arithmetic number, because the mean of its divisors is an integer number (283860).

2^1986978 is an apocalyptic number.

1986978 is an abundant number, since it is smaller than the sum of its proper divisors (2554782).

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

1986978 is a wasteful number, since it uses less digits than its factorization.

1986978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47321.

The product of its digits is 217728, while the sum is 48.

The square root of 1986978 is about 1409.6020715081. The cubic root of 1986978 is about 125.7180645017.

The spelling of 1986978 in words is "one million, nine hundred eighty-six thousand, nine hundred seventy-eight".