31521343121 has 8 divisors (see below), whose sum is σ = 33181999200. Its totient is φ = 29860850880.

The previous prime is 31521343081. The next prime is 31521343153. The reversal of 31521343121 is 12134312513.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31521343121 - 2¹⁴ = 31521326737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31521343621) 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 7 ways as a sum of consecutive naturals, for example, 675110 + ... + 720288.

It is an arithmetic number, because the mean of its divisors is an integer number (4147749900).

Almost surely, 2^31521343121 is an apocalyptic number.

It is an amenable number.

31521343121 is a deficient number, since it is larger than the sum of its proper divisors (1660656079).

31521343121 is a wasteful number, since it uses less digits than its factorization.

31521343121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81919.

The product of its digits is 2160, while the sum is 26.

Adding to 31521343121 its reverse (12134312513), we get a palindrome (43655655634).

The spelling of 31521343121 in words is "thirty-one billion, five hundred twenty-one million, three hundred forty-three thousand, one hundred twenty-one".