21020212313123 has 2 divisors, whose sum is σ = 21020212313124. Its totient is φ = 21020212313122.

The previous prime is 21020212313117. The next prime is 21020212313143. The reversal of 21020212313123 is 32131321202012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21020212313123 - 2⁶ = 21020212313059 is a prime.

It is not a weakly prime, because it can be changed into another prime (21020212313143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510106156561 + 10510106156562.

It is an arithmetic number, because the mean of its divisors is an integer number (10510106156562).

Almost surely, 2^{21020212313123} is an apocalyptic number.

21020212313123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020212313123 is an equidigital number, since it uses as much as digits as its factorization.

21020212313123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21020212313123 its reverse (32131321202012), we get a palindrome (53151533515135).

Subtracting 21020212313123 from its reverse (32131321202012), we obtain a square (11111108888889 = 3333333²).

It can be divided in two parts, 2102021 and 2313123, that added together give a palindrome (4415144).

The spelling of 21020212313123 in words is "twenty-one trillion, twenty billion, two hundred twelve million, three hundred thirteen thousand, one hundred twenty-three".