7871521 has 8 divisors (see below), whose sum is σ = 9057600. Its totient is φ = 6700848.

The previous prime is 7871519. The next prime is 7871573. The reversal of 7871521 is 1251787.

It is a happy number.

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

It is not a de Polignac number, because 7871521 - 2¹ = 7871519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7871581) 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, 2731 + ... + 4816.

It is an arithmetic number, because the mean of its divisors is an integer number (1132200).

Almost surely, 2^7871521 is an apocalyptic number.

It is an amenable number.

7871521 is a deficient number, since it is larger than the sum of its proper divisors (1186079).

7871521 is a wasteful number, since it uses less digits than its factorization.

7871521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7703.

The product of its digits is 3920, while the sum is 31.

The square root of 7871521 is about 2805.6231036973. The cubic root of 7871521 is about 198.9235584286.

The spelling of 7871521 in words is "seven million, eight hundred seventy-one thousand, five hundred twenty-one".