1981340 has 24 divisors (see below), whose sum is σ = 4193952. Its totient is φ = 786240.

The previous prime is 1981337. The next prime is 1981349. The reversal of 1981340 is 431891.

It is a super-3 number, since 3×1981340³ = 23334488028810312000, which contains 333 as substring.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2825 + ... + 3455.

It is an arithmetic number, because the mean of its divisors is an integer number (174748).

2^1981340 is an apocalyptic number.

1981340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981340 is an abundant number, since it is smaller than the sum of its proper divisors (2212612).

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

1981340 is a wasteful number, since it uses less digits than its factorization.

1981340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797 (or 795 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1981340 is about 1407.6007956804. The cubic root of 1981340 is about 125.5990445787.

The spelling of 1981340 in words is "one million, nine hundred eighty-one thousand, three hundred forty".