1981408 has 48 divisors (see below), whose sum is σ = 4593456. Its totient is φ = 829440.

The previous prime is 1981403. The next prime is 1981409. The reversal of 1981408 is 8041891.

It is a super-3 number, since 3×1981408³ = 23336890644682407936, which contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1981408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4360 + ... + 4792.

It is an arithmetic number, because the mean of its divisors is an integer number (95697).

2^1981408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1981408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2296728).

1981408 is an abundant number, since it is smaller than the sum of its proper divisors (2612048).

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

1981408 is a wasteful number, since it uses less digits than its factorization.

1981408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467 (or 459 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 1981408 is about 1407.6249500488. The cubic root of 1981408 is about 125.6004814240.

It can be divided in two parts, 198 and 1408, that multiplied together give a square (278784 = 528²).

The spelling of 1981408 in words is "one million, nine hundred eighty-one thousand, four hundred eight".