7991421 has 8 divisors (see below), whose sum is σ = 10903200. Its totient is φ = 5203632.

The previous prime is 7991407. The next prime is 7991437. The reversal of 7991421 is 1241997.

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

It is not a de Polignac number, because 7991421 - 2⁹ = 7990909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7991441) 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, 30846 + ... + 31103.

It is an arithmetic number, because the mean of its divisors is an integer number (1362900).

Almost surely, 2^7991421 is an apocalyptic number.

It is an amenable number.

7991421 is a deficient number, since it is larger than the sum of its proper divisors (2911779).

7991421 is a wasteful number, since it uses less digits than its factorization.

7991421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61995.

The product of its digits is 4536, while the sum is 33.

The square root of 7991421 is about 2826.9101506769. The cubic root of 7991421 is about 199.9284827628.

The spelling of 7991421 in words is "seven million, nine hundred ninety-one thousand, four hundred twenty-one".