20040120509831 has 2 divisors, whose sum is σ = 20040120509832. Its totient is φ = 20040120509830.

The previous prime is 20040120509821. The next prime is 20040120509833. The reversal of 20040120509831 is 13890502104002.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20040120509831 is a prime.

It is a super-2 number, since 2×20040120509831² (a number of 27 digits) contains 22 as substring.

Together with 20040120509833, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20040120509791 and 20040120509800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20040120509833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10020060254915 + 10020060254916.

It is an arithmetic number, because the mean of its divisors is an integer number (10020060254916).

Almost surely, 2^{20040120509831} is an apocalyptic number.

20040120509831 is a deficient number, since it is larger than the sum of its proper divisors (1).

20040120509831 is an equidigital number, since it uses as much as digits as its factorization.

20040120509831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The spelling of 20040120509831 in words is "twenty trillion, forty billion, one hundred twenty million, five hundred nine thousand, eight hundred thirty-one".