1042821 has 16 divisors (see below), whose sum is σ = 1664320. Its totient is φ = 641520.

The previous prime is 1042819. The next prime is 1042829. The reversal of 1042821 is 1282401.

It is not a de Polignac number, because 1042821 - 2¹ = 1042819 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 1042794 and 1042803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1042829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1135 + ... + 1836.

It is an arithmetic number, because the mean of its divisors is an integer number (104020).

2^1042821 is an apocalyptic number.

It is an amenable number.

1042821 is a deficient number, since it is larger than the sum of its proper divisors (621499).

1042821 is a wasteful number, since it uses less digits than its factorization.

1042821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2993 (or 2987 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1042821 is about 1021.1860751107. The cubic root of 1042821 is about 101.4074641752.

The spelling of 1042821 in words is "one million, forty-two thousand, eight hundred twenty-one".