21417625643 has 2 divisors, whose sum is σ = 21417625644. Its totient is φ = 21417625642.

The previous prime is 21417625613. The next prime is 21417625679. The reversal of 21417625643 is 34652671412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21417625643 - 2¹⁴ = 21417609259 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21417625643.

It is not a weakly prime, because it can be changed into another prime (21417625613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10708812821 + 10708812822.

It is an arithmetic number, because the mean of its divisors is an integer number (10708812822).

Almost surely, 2^21417625643 is an apocalyptic number.

21417625643 is a deficient number, since it is larger than the sum of its proper divisors (1).

21417625643 is an equidigital number, since it uses as much as digits as its factorization.

21417625643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 41.

The spelling of 21417625643 in words is "twenty-one billion, four hundred seventeen million, six hundred twenty-five thousand, six hundred forty-three".