1821542 has 4 divisors (see below), whose sum is σ = 2732316. Its totient is φ = 910770.

The previous prime is 1821541. The next prime is 1821551. The reversal of 1821542 is 2451281.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821541) by changing a digit.

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, 455384 + ... + 455387.

It is an arithmetic number, because the mean of its divisors is an integer number (683079).

2^1821542 is an apocalyptic number.

1821542 is a deficient number, since it is larger than the sum of its proper divisors (910774).

1821542 is an equidigital number, since it uses as much as digits as its factorization.

1821542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910773.

The product of its digits is 640, while the sum is 23.

The square root of 1821542 is about 1349.6451385457. The cubic root of 1821542 is about 122.1273864270.

The spelling of 1821542 in words is "one million, eight hundred twenty-one thousand, five hundred forty-two".