7621821 has 6 divisors (see below), whose sum is σ = 11009310. Its totient is φ = 5081208.

The previous prime is 7621813. The next prime is 7621837. The reversal of 7621821 is 1281267.

It can be written as a sum of positive squares in only one way, i.e., 7452900 + 168921 = 2730^2 + 411^2 .

It is not a de Polignac number, because 7621821 - 2³ = 7621813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7621891) 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 5 ways as a sum of consecutive naturals, for example, 423426 + ... + 423443.

It is an arithmetic number, because the mean of its divisors is an integer number (1834885).

Almost surely, 2^7621821 is an apocalyptic number.

It is an amenable number.

7621821 is a deficient number, since it is larger than the sum of its proper divisors (3387489).

7621821 is a wasteful number, since it uses less digits than its factorization.

7621821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846875 (or 846872 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 7621821 is about 2760.7645680137. The cubic root of 7621821 is about 196.7975020752.

The spelling of 7621821 in words is "seven million, six hundred twenty-one thousand, eight hundred twenty-one".