1011821 has 4 divisors (see below), whose sum is σ = 1026144. Its totient is φ = 997500.

The previous prime is 1011817. The next prime is 1011827. The reversal of 1011821 is 1281101.

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 a cyclic number.

It is not a de Polignac number, because 1011821 - 2² = 1011817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1011796 and 1011805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011827) 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, 7055 + ... + 7196.

It is an arithmetic number, because the mean of its divisors is an integer number (256536).

2^1011821 is an apocalyptic number.

It is an amenable number.

1011821 is a deficient number, since it is larger than the sum of its proper divisors (14323).

1011821 is an equidigital number, since it uses as much as digits as its factorization.

1011821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14322.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 1011821 is about 1005.8931354771. The cubic root of 1011821 is about 100.3924908274.

Adding to 1011821 its reverse (1281101), we get a palindrome (2292922).

It can be divided in two parts, 101 and 1821, that multiplied together give a triangular number (183921 = T₆₀₆).

The spelling of 1011821 in words is "one million, eleven thousand, eight hundred twenty-one".