2121231001 has 2 divisors, whose sum is σ = 2121231002. Its totient is φ = 2121231000.

The previous prime is 2121230999. The next prime is 2121231011. The reversal of 2121231001 is 1001321212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1693734025 + 427496976 = 41155^2 + 20676^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121231001 - 2¹ = 2121230999 is a prime.

Together with 2121230999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2121231011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060615500 + 1060615501.

It is an arithmetic number, because the mean of its divisors is an integer number (1060615501).

Almost surely, 2^2121231001 is an apocalyptic number.

It is an amenable number.

2121231001 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121231001 is an equidigital number, since it uses as much as digits as its factorization.

2121231001 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.

The square root of 2121231001 is about 46056.8236095369. The cubic root of 2121231001 is about 1284.8802547049.

Adding to 2121231001 its reverse (1001321212), we get a palindrome (3122552213).

The spelling of 2121231001 in words is "two billion, one hundred twenty-one million, two hundred thirty-one thousand, one".