2001122621 has 2 divisors, whose sum is σ = 2001122622. Its totient is φ = 2001122620.

The previous prime is 2001122609. The next prime is 2001122663. The reversal of 2001122621 is 1262211002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1599120121 + 402002500 = 39989^2 + 20050^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001122621 - 2²² = 1996928317 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2001122621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001122671) 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, 1000561310 + 1000561311.

It is an arithmetic number, because the mean of its divisors is an integer number (1000561311).

Almost surely, 2^2001122621 is an apocalyptic number.

It is an amenable number.

2001122621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001122621 is an equidigital number, since it uses as much as digits as its factorization.

2001122621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 2001122621 is about 44733.9090735429. The cubic root of 2001122621 is about 1260.1567414398.

Adding to 2001122621 its reverse (1262211002), we get a palindrome (3263333623).

The spelling of 2001122621 in words is "two billion, one million, one hundred twenty-two thousand, six hundred twenty-one".