7988721 has 16 divisors (see below), whose sum is σ = 12075840. Its totient is φ = 4656960.

The previous prime is 7988713. The next prime is 7988723. The reversal of 7988721 is 1278897.

It is not a de Polignac number, because 7988721 - 2³ = 7988713 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (7988723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4650 + ... + 6131.

It is an arithmetic number, because the mean of its divisors is an integer number (754740).

Almost surely, 2^7988721 is an apocalyptic number.

It is an amenable number.

7988721 is a deficient number, since it is larger than the sum of its proper divisors (4087119).

7988721 is a wasteful number, since it uses less digits than its factorization.

7988721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10816.

The product of its digits is 56448, while the sum is 42.

The square root of 7988721 is about 2826.4325571292. The cubic root of 7988721 is about 199.9059641265.

The spelling of 7988721 in words is "seven million, nine hundred eighty-eight thousand, seven hundred twenty-one".