3978390 has 48 divisors (see below), whose sum is σ = 10385424. Its totient is φ = 969600.

The previous prime is 3978349. The next prime is 3978421. The reversal of 3978390 is 938793.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

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, 39340 + ... + 39440.

It is an arithmetic number, because the mean of its divisors is an integer number (216363).

Almost surely, 2^3978390 is an apocalyptic number.

3978390 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 3978390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5192712).

3978390 is an abundant number, since it is smaller than the sum of its proper divisors (6407034).

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

3978390 is a wasteful number, since it uses less digits than its factorization.

3978390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 3978390 is about 1994.5901834713. The cubic root of 3978390 is about 158.4537243791.

The spelling of 3978390 in words is "three million, nine hundred seventy-eight thousand, three hundred ninety".