1981534 has 4 divisors (see below), whose sum is σ = 2972304. Its totient is φ = 990766.

The previous prime is 1981523. The next prime is 1981543. The reversal of 1981534 is 4351891.

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

It is a junction number, because it is equal to n+sod(n) for n = 1981496 and 1981505.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 495382 + ... + 495385.

It is an arithmetic number, because the mean of its divisors is an integer number (743076).

2^1981534 is an apocalyptic number.

1981534 is a deficient number, since it is larger than the sum of its proper divisors (990770).

1981534 is an equidigital number, since it uses as much as digits as its factorization.

1981534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990769.

The product of its digits is 4320, while the sum is 31.

The square root of 1981534 is about 1407.6697055773. The cubic root of 1981534 is about 125.6031437270.

The spelling of 1981534 in words is "one million, nine hundred eighty-one thousand, five hundred thirty-four".