21123100312001 has 2 divisors, whose sum is σ = 21123100312002. Its totient is φ = 21123100312000.

The previous prime is 21123100311983. The next prime is 21123100312019. The reversal of 21123100312001 is 10021300132112.

It is a balanced prime because it is at equal distance from previous prime (21123100311983) and next prime (21123100312019).

It can be written as a sum of positive squares in only one way, i.e., 21111736752001 + 11363560000 = 4594751^2 + 106600^2 .

It is a cyclic number.

It is not a de Polignac number, because 21123100312001 - 2¹⁴ = 21123100295617 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21123102312001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561550156000 + 10561550156001.

It is an arithmetic number, because the mean of its divisors is an integer number (10561550156001).

Almost surely, 2^{21123100312001} is an apocalyptic number.

It is an amenable number.

21123100312001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123100312001 is an equidigital number, since it uses as much as digits as its factorization.

21123100312001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21123100312001 its reverse (10021300132112), we get a palindrome (31144400444113).

The spelling of 21123100312001 in words is "twenty-one trillion, one hundred twenty-three billion, one hundred million, three hundred twelve thousand, one".