1235821 has 2 divisors, whose sum is σ = 1235822. Its totient is φ = 1235820.

The previous prime is 1235807. The next prime is 1235831. The reversal of 1235821 is 1285321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1232100 + 3721 = 1110^2 + 61^2 .

It is a cyclic number.

It is not a de Polignac number, because 1235821 - 2⁵ = 1235789 is a prime.

It is a Chen prime.

It is a plaindrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 1235792 and 1235801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1235831) 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, 617910 + 617911.

It is an arithmetic number, because the mean of its divisors is an integer number (617911).

2^1235821 is an apocalyptic number.

It is an amenable number.

1235821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1235821 is an equidigital number, since it uses as much as digits as its factorization.

1235821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 22.

The square root of 1235821 is about 1111.6748625385. The cubic root of 1235821 is about 107.3128816230.

The spelling of 1235821 in words is "one million, two hundred thirty-five thousand, eight hundred twenty-one".