21680957759 has 2 divisors, whose sum is σ = 21680957760. Its totient is φ = 21680957758.

The previous prime is 21680957663. The next prime is 21680957801. The reversal of 21680957759 is 95775908612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21680957759 - 2¹⁶ = 21680892223 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21680957698 and 21680957707.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21680957959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10840478879 + 10840478880.

It is an arithmetic number, because the mean of its divisors is an integer number (10840478880).

Almost surely, 2^21680957759 is an apocalyptic number.

21680957759 is a deficient number, since it is larger than the sum of its proper divisors (1).

21680957759 is an equidigital number, since it uses as much as digits as its factorization.

21680957759 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9525600, while the sum is 59.

The spelling of 21680957759 in words is "twenty-one billion, six hundred eighty million, nine hundred fifty-seven thousand, seven hundred fifty-nine".