21030120031 has 2 divisors, whose sum is σ = 21030120032. Its totient is φ = 21030120030.

The previous prime is 21030119993. The next prime is 21030120091. The reversal of 21030120031 is 13002103012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21030120031 - 2²¹ = 21028022879 is a prime.

It is a super-2 number, since 2×21030120031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21030119993 and 21030120020.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21030120091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515060015 + 10515060016.

It is an arithmetic number, because the mean of its divisors is an integer number (10515060016).

Almost surely, 2^21030120031 is an apocalyptic number.

21030120031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030120031 is an equidigital number, since it uses as much as digits as its factorization.

21030120031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 21030120031 its reverse (13002103012), we get a palindrome (34032223043).

The spelling of 21030120031 in words is "twenty-one billion, thirty million, one hundred twenty thousand, thirty-one".