1275821 has 4 divisors (see below), whose sum is σ = 1293372. Its totient is φ = 1258272.

The previous prime is 1275817. The next prime is 1275823. The reversal of 1275821 is 1285721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1285721 = 149 ⋅8629.

It can be written as a sum of positive squares in 2 ways, for example, as 373321 + 902500 = 611^2 + 950^2 .

It is a cyclic number.

It is not a de Polignac number, because 1275821 - 2² = 1275817 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1275823) 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, 8666 + ... + 8811.

It is an arithmetic number, because the mean of its divisors is an integer number (323343).

2^1275821 is an apocalyptic number.

It is an amenable number.

1275821 is a deficient number, since it is larger than the sum of its proper divisors (17551).

1275821 is an equidigital number, since it uses as much as digits as its factorization.

1275821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17550.

The product of its digits is 1120, while the sum is 26.

The square root of 1275821 is about 1129.5224654694. The cubic root of 1275821 is about 108.4584138447.

The spelling of 1275821 in words is "one million, two hundred seventy-five thousand, eight hundred twenty-one".