1206821 has 12 divisors (see below), whose sum is σ = 1532160. Its totient is φ = 939960.

The previous prime is 1206809. The next prime is 1206827. The reversal of 1206821 is 1286021.

It is not a de Polignac number, because 1206821 - 2¹⁸ = 944677 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1206793 and 1206802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1206827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 581 + ... + 1658.

It is an arithmetic number, because the mean of its divisors is an integer number (127680).

2^1206821 is an apocalyptic number.

1206821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1206821 is a deficient number, since it is larger than the sum of its proper divisors (325339).

1206821 is a wasteful number, since it uses less digits than its factorization.

1206821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2264 (or 2257 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 1206821 is about 1098.5540496489. The cubic root of 1206821 is about 106.4668209075.

The spelling of 1206821 in words is "one million, two hundred six thousand, eight hundred twenty-one".