21021102031 has 2 divisors, whose sum is σ = 21021102032. Its totient is φ = 21021102030.

The previous prime is 21021102013. The next prime is 21021102061. The reversal of 21021102031 is 13020112012.

Together with previous prime (21021102013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21021102031 - 2⁵ = 21021101999 is a prime.

It is a super-2 number, since 2×21021102031² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021102001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510551015 + 10510551016.

It is an arithmetic number, because the mean of its divisors is an integer number (10510551016).

Almost surely, 2^21021102031 is an apocalyptic number.

21021102031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021102031 is an equidigital number, since it uses as much as digits as its factorization.

21021102031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21021102031 its reverse (13020112012), we get a palindrome (34041214043).

The spelling of 21021102031 in words is "twenty-one billion, twenty-one million, one hundred two thousand, thirty-one".