2101619561 has 2 divisors, whose sum is σ = 2101619562. Its totient is φ = 2101619560.

The previous prime is 2101619497. The next prime is 2101619563. The reversal of 2101619561 is 1659161012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1566576400 + 535043161 = 39580^2 + 23131^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101619561 - 2⁶ = 2101619497 is a prime.

Together with 2101619563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2101619563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050809780 + 1050809781.

It is an arithmetic number, because the mean of its divisors is an integer number (1050809781).

Almost surely, 2^2101619561 is an apocalyptic number.

It is an amenable number.

2101619561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101619561 is an equidigital number, since it uses as much as digits as its factorization.

2101619561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 32.

The square root of 2101619561 is about 45843.4244030701. The cubic root of 2101619561 is about 1280.9082829459.

The spelling of 2101619561 in words is "two billion, one hundred one million, six hundred nineteen thousand, five hundred sixty-one".