1978140 has 24 divisors (see below), whose sum is σ = 5538960. Its totient is φ = 527488.

The previous prime is 1978117. The next prime is 1978153. The reversal of 1978140 is 418791.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1978098 and 1978107.

It is a congruent number.

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, 16425 + ... + 16544.

It is an arithmetic number, because the mean of its divisors is an integer number (230790).

2^1978140 is an apocalyptic number.

1978140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1978140 is an abundant number, since it is smaller than the sum of its proper divisors (3560820).

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

1978140 is a wasteful number, since it uses less digits than its factorization.

1978140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32981 (or 32979 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 1978140 is about 1406.4636504368. The cubic root of 1978140 is about 125.5313911200.

The spelling of 1978140 in words is "one million, nine hundred seventy-eight thousand, one hundred forty".