31520072243 has 4 divisors (see below), whose sum is σ = 34385533368. Its totient is φ = 28654611120.

The previous prime is 31520072237. The next prime is 31520072261. The reversal of 31520072243 is 34227002513.

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

It is a cyclic number.

It is not a de Polignac number, because 31520072243 - 2¹² = 31520068147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31520072263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1432730546 + ... + 1432730567.

It is an arithmetic number, because the mean of its divisors is an integer number (8596383342).

Almost surely, 2^31520072243 is an apocalyptic number.

31520072243 is a deficient number, since it is larger than the sum of its proper divisors (2865461125).

31520072243 is a wasteful number, since it uses less digits than its factorization.

31520072243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2865461124.

The product of its (nonzero) digits is 10080, while the sum is 29.

Adding to 31520072243 its reverse (34227002513), we get a palindrome (65747074756).

The spelling of 31520072243 in words is "thirty-one billion, five hundred twenty million, seventy-two thousand, two hundred forty-three".