5781321 has 48 divisors (see below), whose sum is σ = 10657920. Its totient is φ = 3032640.

The previous prime is 5781319. The next prime is 5781323. The reversal of 5781321 is 1231875.

It is an interprime number because it is at equal distance from previous prime (5781319) and next prime (5781323).

It is not a de Polignac number, because 5781321 - 2¹ = 5781319 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (5781323) 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 47 ways as a sum of consecutive naturals, for example, 31851 + ... + 32031.

It is an arithmetic number, because the mean of its divisors is an integer number (222040).

Almost surely, 2^5781321 is an apocalyptic number.

5781321 is the 1521-st heptagonal number.

It is an amenable number.

5781321 is a deficient number, since it is larger than the sum of its proper divisors (4876599).

5781321 is a wasteful number, since it uses less digits than its factorization.

5781321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223 (or 204 counting only the distinct ones).

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

The square root of 5781321 is about 2404.4377721205. The cubic root of 5781321 is about 179.4770935199.

It can be divided in two parts, 5781 and 321, that multiplied together give a triangular number (1855701 = T₁₉₂₆).

The spelling of 5781321 in words is "five million, seven hundred eighty-one thousand, three hundred twenty-one".