2021617261 has 2 divisors, whose sum is σ = 2021617262. Its totient is φ = 2021617260.

The previous prime is 2021617259. The next prime is 2021617343. The reversal of 2021617261 is 1627161202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1896602500 + 125014761 = 43550^2 + 11181^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021617261 - 2¹ = 2021617259 is a prime.

Together with 2021617259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021612261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010808630 + 1010808631.

It is an arithmetic number, because the mean of its divisors is an integer number (1010808631).

Almost surely, 2^2021617261 is an apocalyptic number.

It is an amenable number.

2021617261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021617261 is an equidigital number, since it uses as much as digits as its factorization.

2021617261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 2021617261 is about 44962.3983012472. The cubic root of 2021617261 is about 1264.4441330776. Note that the first 3 decimals are identical.

Adding to 2021617261 its reverse (1627161202), we get a palindrome (3648778463).

The spelling of 2021617261 in words is "two billion, twenty-one million, six hundred seventeen thousand, two hundred sixty-one".