1981594 has 4 divisors (see below), whose sum is σ = 2972394. Its totient is φ = 990796.

The previous prime is 1981589. The next prime is 1981597. The reversal of 1981594 is 4951891.

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

It can be written as a sum of positive squares in only one way, i.e., 1974025 + 7569 = 1405^2 + 87^2 .

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (1981597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495397 + ... + 495400.

2^1981594 is an apocalyptic number.

1981594 is a deficient number, since it is larger than the sum of its proper divisors (990800).

1981594 is an equidigital number, since it uses as much as digits as its factorization.

1981594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990799.

The product of its digits is 12960, while the sum is 37.

The square root of 1981594 is about 1407.6910172335. The cubic root of 1981594 is about 125.6044114507.

The spelling of 1981594 in words is "one million, nine hundred eighty-one thousand, five hundred ninety-four".