31203020121311 has 4 divisors (see below), whose sum is σ = 31203268447512. Its totient is φ = 31202771795112.

The previous prime is 31203020121277. The next prime is 31203020121353. The reversal of 31203020121311 is 11312102030213.

It is a happy number.

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-31203020121311 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 (31203020121811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123974525 + ... + 124225958.

It is an arithmetic number, because the mean of its divisors is an integer number (7800817111878).

Almost surely, 2^{31203020121311} is an apocalyptic number.

31203020121311 is a deficient number, since it is larger than the sum of its proper divisors (248326201).

31203020121311 is a wasteful number, since it uses less digits than its factorization.

31203020121311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248326200.

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

Adding to 31203020121311 its reverse (11312102030213), we get a palindrome (42515122151524).

The spelling of 31203020121311 in words is "thirty-one trillion, two hundred three billion, twenty million, one hundred twenty-one thousand, three hundred eleven".