1981535 has 8 divisors (see below), whose sum is σ = 2442336. Its totient is φ = 1542240.

The previous prime is 1981523. The next prime is 1981543. The reversal of 1981535 is 5351891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1981535 - 2⁶ = 1981471 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5171 + ... + 5540.

It is an arithmetic number, because the mean of its divisors is an integer number (305292).

2^1981535 is an apocalyptic number.

1981535 is a deficient number, since it is larger than the sum of its proper divisors (460801).

1981535 is a wasteful number, since it uses less digits than its factorization.

1981535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10753.

The product of its digits is 5400, while the sum is 32.

The square root of 1981535 is about 1407.6700607742. The cubic root of 1981535 is about 125.6031648559.

The spelling of 1981535 in words is "one million, nine hundred eighty-one thousand, five hundred thirty-five".