7406821 has 2 divisors, whose sum is σ = 7406822. Its totient is φ = 7406820.

The previous prime is 7406807. The next prime is 7406843. The reversal of 7406821 is 1286047.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5336100 + 2070721 = 2310^2 + 1439^2 .

It is a cyclic number.

It is not a de Polignac number, because 7406821 - 2⁹ = 7406309 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7406821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7406881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3703410 + 3703411.

It is an arithmetic number, because the mean of its divisors is an integer number (3703411).

Almost surely, 2^7406821 is an apocalyptic number.

It is an amenable number.

7406821 is a deficient number, since it is larger than the sum of its proper divisors (1).

7406821 is an equidigital number, since it uses as much as digits as its factorization.

7406821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 7406821 is about 2721.5475377072. The cubic root of 7406821 is about 194.9293717481.

The spelling of 7406821 in words is "seven million, four hundred six thousand, eight hundred twenty-one".