21245604739 has 2 divisors, whose sum is σ = 21245604740. Its totient is φ = 21245604738.

The previous prime is 21245604707. The next prime is 21245604773. The reversal of 21245604739 is 93740654212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21245604739 - 2⁵ = 21245604707 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21245604695 and 21245604704.

It is not a weakly prime, because it can be changed into another prime (21245604239) 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, 10622802369 + 10622802370.

It is an arithmetic number, because the mean of its divisors is an integer number (10622802370).

Almost surely, 2^21245604739 is an apocalyptic number.

21245604739 is a deficient number, since it is larger than the sum of its proper divisors (1).

21245604739 is an equidigital number, since it uses as much as digits as its factorization.

21245604739 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 43.

The spelling of 21245604739 in words is "twenty-one billion, two hundred forty-five million, six hundred four thousand, seven hundred thirty-nine".