5431247821 has 4 divisors (see below), whose sum is σ = 5456988544. Its totient is φ = 5405507100.

The previous prime is 5431247813. The next prime is 5431247849. The reversal of 5431247821 is 1287421345.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 5431247821 - 2³ = 5431247813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5431247851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12870045 + ... + 12870466.

It is an arithmetic number, because the mean of its divisors is an integer number (1364247136).

Almost surely, 2^5431247821 is an apocalyptic number.

It is an amenable number.

5431247821 is a deficient number, since it is larger than the sum of its proper divisors (25740723).

5431247821 is a wasteful number, since it uses less digits than its factorization.

5431247821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25740722.

The product of its digits is 53760, while the sum is 37.

The square root of 5431247821 is about 73697.0000814144. Note that the first 4 decimals coincide. The cubic root of 5431247821 is about 1757.7881802348.

The spelling of 5431247821 in words is "five billion, four hundred thirty-one million, two hundred forty-seven thousand, eight hundred twenty-one".