7851321 has 6 divisors (see below), whose sum is σ = 11340810. Its totient is φ = 5234208.

The previous prime is 7851317. The next prime is 7851323. The reversal of 7851321 is 1231587.

It can be written as a sum of positive squares in only one way, i.e., 6969600 + 881721 = 2640^2 + 939^2 .

It is not a de Polignac number, because 7851321 - 2² = 7851317 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7851323) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 436176 + ... + 436193.

It is an arithmetic number, because the mean of its divisors is an integer number (1890135).

Almost surely, 2^7851321 is an apocalyptic number.

It is an amenable number.

7851321 is a deficient number, since it is larger than the sum of its proper divisors (3489489).

7851321 is a wasteful number, since it uses less digits than its factorization.

7851321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872375 (or 872372 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 7851321 is about 2802.0208778665. The cubic root of 7851321 is about 198.7532525871.

The spelling of 7851321 in words is "seven million, eight hundred fifty-one thousand, three hundred twenty-one".