31573319909 has 4 divisors (see below), whose sum is σ = 31577217804. Its totient is φ = 31569422016.

The previous prime is 31573319839. The next prime is 31573319917. The reversal of 31573319909 is 90991337513.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90991337513 = 25583 ⋅3556711.

It can be written as a sum of positive squares in 2 ways, for example, as 20255551684 + 11317768225 = 142322^2 + 106385^2 .

It is a cyclic number.

It is not a de Polignac number, because 31573319909 - 2¹⁶ = 31573254373 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 (31573319929) 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, 1936772 + ... + 1953005.

It is an arithmetic number, because the mean of its divisors is an integer number (7894304451).

Almost surely, 2^31573319909 is an apocalyptic number.

It is an amenable number.

31573319909 is a deficient number, since it is larger than the sum of its proper divisors (3897895).

31573319909 is an equidigital number, since it uses as much as digits as its factorization.

31573319909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3897894.

The product of its (nonzero) digits is 688905, while the sum is 50.

The spelling of 31573319909 in words is "thirty-one billion, five hundred seventy-three million, three hundred nineteen thousand, nine hundred nine".