1026721 has 4 divisors (see below), whose sum is σ = 1031472. Its totient is φ = 1021972.

The previous prime is 1026709. The next prime is 1026733. The reversal of 1026721 is 1276201.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1276201 = 23 ⋅55487.

It is an interprime number because it is at equal distance from previous prime (1026709) and next prime (1026733).

It is a cyclic number.

It is not a de Polignac number, because 1026721 - 2⁷ = 1026593 is a prime.

It is a super-4 number, since 4×1026721⁴ (a number of 25 digits) contains 4444 as substring.

It is a Duffinian number.

1026721 is a lucky number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (1026761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2035 + ... + 2488.

It is an arithmetic number, because the mean of its divisors is an integer number (257868).

2^1026721 is an apocalyptic number.

It is an amenable number.

1026721 is a deficient number, since it is larger than the sum of its proper divisors (4751).

1026721 is an equidigital number, since it uses as much as digits as its factorization.

1026721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4750.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 1026721 is about 1013.2724214149. The cubic root of 1026721 is about 100.8828822497.

The spelling of 1026721 in words is "one million, twenty-six thousand, seven hundred twenty-one".