1981438 has 4 divisors (see below), whose sum is σ = 2972160. Its totient is φ = 990718.

The previous prime is 1981429. The next prime is 1981457. The reversal of 1981438 is 8341891.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a super-3 number, since 3×1981438³ = 23337950674700759016, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495358 + ... + 495361.

It is an arithmetic number, because the mean of its divisors is an integer number (743040).

2^1981438 is an apocalyptic number.

1981438 is a deficient number, since it is larger than the sum of its proper divisors (990722).

1981438 is an equidigital number, since it uses as much as digits as its factorization.

1981438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990721.

The product of its digits is 6912, while the sum is 34.

The square root of 1981438 is about 1407.6356062561. The cubic root of 1981438 is about 125.6011153159.

The spelling of 1981438 in words is "one million, nine hundred eighty-one thousand, four hundred thirty-eight".