2531278643 has 4 divisors (see below), whose sum is σ = 2531790000. Its totient is φ = 2530767288.

The previous prime is 2531278621. The next prime is 2531278649. The reversal of 2531278643 is 3468721352.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2531278643 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2531278643.

It is not an unprimeable number, because it can be changed into a prime (2531278649) 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, 248180 + ... + 258177.

It is an arithmetic number, because the mean of its divisors is an integer number (632947500).

Almost surely, 2^2531278643 is an apocalyptic number.

2531278643 is a deficient number, since it is larger than the sum of its proper divisors (511357).

2531278643 is an equidigital number, since it uses as much as digits as its factorization.

2531278643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511356.

The product of its digits is 241920, while the sum is 41.

The square root of 2531278643 is about 50311.8141493626. The cubic root of 2531278643 is about 1362.8455851267.

Adding to 2531278643 its reverse (3468721352), we get a palindrome (5999999995).

The spelling of 2531278643 in words is "two billion, five hundred thirty-one million, two hundred seventy-eight thousand, six hundred forty-three".