7800721 has 8 divisors (see below), whose sum is σ = 7925760. Its totient is φ = 7676928.

The previous prime is 7800649. The next prime is 7800733. The reversal of 7800721 is 1270087.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7800721 - 2¹¹ = 7798673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7800781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30225 + ... + 30481.

It is an arithmetic number, because the mean of its divisors is an integer number (990720).

Almost surely, 2^7800721 is an apocalyptic number.

It is an amenable number.

7800721 is a deficient number, since it is larger than the sum of its proper divisors (125039).

7800721 is a wasteful number, since it uses less digits than its factorization.

7800721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623.

The product of its (nonzero) digits is 784, while the sum is 25.

The square root of 7800721 is about 2792.9770854771. The cubic root of 7800721 is about 198.3253586857.

The spelling of 7800721 in words is "seven million, eight hundred thousand, seven hundred twenty-one".