1542821 has 4 divisors (see below), whose sum is σ = 1763232. Its totient is φ = 1322412.

The previous prime is 1542811. The next prime is 1542823. The reversal of 1542821 is 1282451.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1542821 - 2¹⁰ = 1541797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1542823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110195 + ... + 110208.

It is an arithmetic number, because the mean of its divisors is an integer number (440808).

2^1542821 is an apocalyptic number.

It is an amenable number.

1542821 is a deficient number, since it is larger than the sum of its proper divisors (220411).

1542821 is an equidigital number, since it uses as much as digits as its factorization.

1542821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220410.

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

The square root of 1542821 is about 1242.1034578488. The cubic root of 1542821 is about 115.5505048266.

It can be divided in two parts, 154 and 2821, that multiplied together give a palindrome (434434).

The spelling of 1542821 in words is "one million, five hundred forty-two thousand, eight hundred twenty-one".