21916151617 has 2 divisors, whose sum is σ = 21916151618. Its totient is φ = 21916151616.

The previous prime is 21916151557. The next prime is 21916151633. The reversal of 21916151617 is 71615161912.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20883429121 + 1032722496 = 144511^2 + 32136^2 .

It is a cyclic number.

It is not a de Polignac number, because 21916151617 - 2¹¹ = 21916149569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21916151617.

It is not a weakly prime, because it can be changed into another prime (21916151017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10958075808 + 10958075809.

It is an arithmetic number, because the mean of its divisors is an integer number (10958075809).

Almost surely, 2^21916151617 is an apocalyptic number.

It is an amenable number.

21916151617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21916151617 is an equidigital number, since it uses as much as digits as its factorization.

21916151617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 40.

The spelling of 21916151617 in words is "twenty-one billion, nine hundred sixteen million, one hundred fifty-one thousand, six hundred seventeen".