1978620 has 72 divisors (see below), whose sum is σ = 6454224. Its totient is φ = 451584.

The previous prime is 1978597. The next prime is 1978631. The reversal of 1978620 is 268791.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2604 + ... + 3276.

It is an arithmetic number, because the mean of its divisors is an integer number (89642).

2^1978620 is an apocalyptic number.

1978620 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 1978620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3227112).

1978620 is an abundant number, since it is smaller than the sum of its proper divisors (4475604).

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

1978620 is a wasteful number, since it uses less digits than its factorization.

1978620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699 (or 690 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 1978620 is about 1406.6342808278. The cubic root of 1978620 is about 125.5415437878.

The spelling of 1978620 in words is "one million, nine hundred seventy-eight thousand, six hundred twenty".