21645460139 has 2 divisors, whose sum is σ = 21645460140. Its totient is φ = 21645460138.

The previous prime is 21645460129. The next prime is 21645460141. The reversal of 21645460139 is 93106454612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21645460139 is a prime.

Together with 21645460141, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21645460096 and 21645460105.

It is not a weakly prime, because it can be changed into another prime (21645460129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10822730069 + 10822730070.

It is an arithmetic number, because the mean of its divisors is an integer number (10822730070).

Almost surely, 2^21645460139 is an apocalyptic number.

21645460139 is a deficient number, since it is larger than the sum of its proper divisors (1).

21645460139 is an equidigital number, since it uses as much as digits as its factorization.

21645460139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 41.

The spelling of 21645460139 in words is "twenty-one billion, six hundred forty-five million, four hundred sixty thousand, one hundred thirty-nine".