1978240 has 64 divisors (see below), whose sum is σ = 5177520. Its totient is φ = 716800.

The previous prime is 1978219. The next prime is 1978267. The reversal of 1978240 is 428791.

It is a tau number, because it is divible by the number of its divisors (64).

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, 6900 + ... + 7180.

2^1978240 is an apocalyptic number.

1978240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2588760).

1978240 is an abundant number, since it is smaller than the sum of its proper divisors (3199280).

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

1978240 is a wasteful number, since it uses less digits than its factorization.

1978240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 1978240 is about 1406.4992001420. The cubic root of 1978240 is about 125.5335063946.

The spelling of 1978240 in words is "one million, nine hundred seventy-eight thousand, two hundred forty".