21424463617 has 2 divisors, whose sum is σ = 21424463618. Its totient is φ = 21424463616.

The previous prime is 21424463611. The next prime is 21424463629. The reversal of 21424463617 is 71636442412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14593606416 + 6830857201 = 120804^2 + 82649^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21424463617 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21424463617.

It is not a weakly prime, because it can be changed into another prime (21424463611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712231808 + 10712231809.

It is an arithmetic number, because the mean of its divisors is an integer number (10712231809).

Almost surely, 2^21424463617 is an apocalyptic number.

It is an amenable number.

21424463617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424463617 is an equidigital number, since it uses as much as digits as its factorization.

21424463617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 40.

The spelling of 21424463617 in words is "twenty-one billion, four hundred twenty-four million, four hundred sixty-three thousand, six hundred seventeen".