21012003031 has 2 divisors, whose sum is σ = 21012003032. Its totient is φ = 21012003030.

The previous prime is 21012003013. The next prime is 21012003037. The reversal of 21012003031 is 13030021012.

Together with previous prime (21012003013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21012003031 - 2⁷ = 21012002903 is a prime.

It is a super-2 number, since 2×21012003031² (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 (21012003037) 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 as a sum of consecutive naturals, namely, 10506001515 + 10506001516.

It is an arithmetic number, because the mean of its divisors is an integer number (10506001516).

Almost surely, 2^21012003031 is an apocalyptic number.

21012003031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012003031 is an equidigital number, since it uses as much as digits as its factorization.

21012003031 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 21012003031 its reverse (13030021012), we get a palindrome (34042024043).

The spelling of 21012003031 in words is "twenty-one billion, twelve million, three thousand, thirty-one".