1981536 has 24 divisors (see below), whose sum is σ = 5201784. Its totient is φ = 660480.

The previous prime is 1981523. The next prime is 1981543. The reversal of 1981536 is 6351891.

It is a tau number, because it is divible by the number of its divisors (24).

It is an Ulam number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 1981497 and 1981506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10225 + ... + 10416.

It is an arithmetic number, because the mean of its divisors is an integer number (216741).

2^1981536 is an apocalyptic number.

1981536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1981536 is an abundant number, since it is smaller than the sum of its proper divisors (3220248).

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

1981536 is a wasteful number, since it uses less digits than its factorization.

1981536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20654 (or 20646 counting only the distinct ones).

The product of its digits is 6480, while the sum is 33.

The square root of 1981536 is about 1407.6704159710. The cubic root of 1981536 is about 125.6031859849.

The spelling of 1981536 in words is "one million, nine hundred eighty-one thousand, five hundred thirty-six".