21120123001 has 2 divisors, whose sum is σ = 21120123002. Its totient is φ = 21120123000.

The previous prime is 21120122981. The next prime is 21120123007. The reversal of 21120123001 is 10032102112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21119355625 + 767376 = 145325^2 + 876^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120123001 - 2⁹ = 21120122489 is a prime.

It is not a weakly prime, because it can be changed into another prime (21120123007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560061500 + 10560061501.

It is an arithmetic number, because the mean of its divisors is an integer number (10560061501).

Almost surely, 2^21120123001 is an apocalyptic number.

It is an amenable number.

21120123001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120123001 is an equidigital number, since it uses as much as digits as its factorization.

21120123001 is an evil number, because the sum of its binary digits is even.

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

Adding to 21120123001 its reverse (10032102112), we get a palindrome (31152225113).

The spelling of 21120123001 in words is "twenty-one billion, one hundred twenty million, one hundred twenty-three thousand, one".