7826721 has 24 divisors (see below), whose sum is σ = 12476160. Its totient is φ = 4348512.

The previous prime is 7826713. The next prime is 7826737. The reversal of 7826721 is 1276287.

It is not a de Polignac number, because 7826721 - 2³ = 7826713 is a prime.

It is a super-2 number, since 2×7826721² = 122515123223682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7826701) 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 in 23 ways as a sum of consecutive naturals, for example, 4720 + ... + 6158.

It is an arithmetic number, because the mean of its divisors is an integer number (519840).

Almost surely, 2^7826721 is an apocalyptic number.

It is an amenable number.

7826721 is a deficient number, since it is larger than the sum of its proper divisors (4649439).

7826721 is a wasteful number, since it uses less digits than its factorization.

7826721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1493 (or 1486 counting only the distinct ones).

The product of its digits is 9408, while the sum is 33.

The square root of 7826721 is about 2797.6277450726. The cubic root of 7826721 is about 198.5454554793.

It can be divided in two parts, 782 and 6721, that added together give a triangular number (7503 = T₁₂₂).

The spelling of 7826721 in words is "seven million, eight hundred twenty-six thousand, seven hundred twenty-one".