7971387 has 4 divisors (see below), whose sum is σ = 10628520. Its totient is φ = 5314256.

The previous prime is 7971373. The next prime is 7971389. The reversal of 7971387 is 7831797.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 7971387 - 2⁶ = 7971323 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7971389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1328562 + ... + 1328567.

It is an arithmetic number, because the mean of its divisors is an integer number (2657130).

Almost surely, 2^7971387 is an apocalyptic number.

7971387 is a deficient number, since it is larger than the sum of its proper divisors (2657133).

7971387 is a wasteful number, since it uses less digits than its factorization.

7971387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2657132.

The product of its digits is 74088, while the sum is 42.

The square root of 7971387 is about 2823.3644823154. The cubic root of 7971387 is about 199.7612734950.

It can be divided in two parts, 79713 and 87, that added together give a triangular number (79800 = T₃₉₉).

The spelling of 7971387 in words is "seven million, nine hundred seventy-one thousand, three hundred eighty-seven".