1981069 has 4 divisors (see below), whose sum is σ = 1984444. Its totient is φ = 1977696.

The previous prime is 1981037. The next prime is 1981081. The reversal of 1981069 is 9601891.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1664100 + 316969 = 1290^2 + 563^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981069 - 2⁵ = 1981037 is a prime.

It is a super-2 number, since 2×1981069² = 7849268765522, which contains 22 as substring.

It is a Duffinian number.

1981069 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 552 + ... + 2065.

It is an arithmetic number, because the mean of its divisors is an integer number (496111).

2^1981069 is an apocalyptic number.

It is an amenable number.

1981069 is a deficient number, since it is larger than the sum of its proper divisors (3375).

1981069 is an equidigital number, since it uses as much as digits as its factorization.

1981069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3374.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 1981069 is about 1407.5045293000. The cubic root of 1981069 is about 125.5933180009.

The spelling of 1981069 in words is "one million, nine hundred eighty-one thousand, sixty-nine".