31123131220001 has 4 divisors (see below), whose sum is σ = 31142260374192. Its totient is φ = 31104002065812.

The previous prime is 31123131219977. The next prime is 31123131220007. The reversal of 31123131220001 is 10002213132113.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-31123131220001 is a prime.

It is a super-3 number, since 3×31123131220001³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31123131220007) 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, 9564574655 + ... + 9564577908.

It is an arithmetic number, because the mean of its divisors is an integer number (7785565093548).

Almost surely, 2^{31123131220001} is an apocalyptic number.

It is an amenable number.

31123131220001 is a deficient number, since it is larger than the sum of its proper divisors (19129154191).

31123131220001 is a wasteful number, since it uses less digits than its factorization.

31123131220001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19129154190.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 31123131220001 its reverse (10002213132113), we get a palindrome (41125344352114).

The spelling of 31123131220001 in words is "thirty-one trillion, one hundred twenty-three billion, one hundred thirty-one million, two hundred twenty thousand, one".