1978020 has 144 divisors (see below), whose sum is σ = 6971328. Its totient is φ = 466560.

The previous prime is 1977991. The next prime is 1978021. The reversal of 1978020 is 208791.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1978021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 53442 + ... + 53478.

It is an arithmetic number, because the mean of its divisors is an integer number (48412).

2^1978020 is an apocalyptic number.

1978020 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 1978020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3485664).

1978020 is an abundant number, since it is smaller than the sum of its proper divisors (4993308).

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

1978020 is a wasteful number, since it uses less digits than its factorization.

1978020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 1978020 is about 1406.4209896045. The cubic root of 1978020 is about 125.5288526965.

The spelling of 1978020 in words is "one million, nine hundred seventy-eight thousand, twenty".