7958721 has 8 divisors (see below), whose sum is σ = 10626304. Its totient is φ = 5298480.

The previous prime is 7958693. The next prime is 7958749. The reversal of 7958721 is 1278597.

It is an interprime number because it is at equal distance from previous prime (7958693) and next prime (7958749).

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

It is not a de Polignac number, because 7958721 - 2⁵ = 7958689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7958721.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7958761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1635 + ... + 4311.

It is an arithmetic number, because the mean of its divisors is an integer number (1328288).

Almost surely, 2^7958721 is an apocalyptic number.

It is an amenable number.

7958721 is a deficient number, since it is larger than the sum of its proper divisors (2667583).

7958721 is a wasteful number, since it uses less digits than its factorization.

7958721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3671.

The product of its digits is 35280, while the sum is 39.

The square root of 7958721 is about 2821.1205220621. The cubic root of 7958721 is about 199.6554149801.

Adding to 7958721 its product of digits (35280), we get a triangular number (7994001 = T₃₉₉₈).

The spelling of 7958721 in words is "seven million, nine hundred fifty-eight thousand, seven hundred twenty-one".