21464605709 has 2 divisors, whose sum is σ = 21464605710. Its totient is φ = 21464605708.

The previous prime is 21464605571. The next prime is 21464605753. The reversal of 21464605709 is 90750646412.

It is an a-pointer prime, because the next prime (21464605753) can be obtained adding 21464605709 to its sum of digits (44).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11493984100 + 9970621609 = 107210^2 + 99853^2 .

It is a cyclic number.

It is not a de Polignac number, because 21464605709 - 2¹⁶ = 21464540173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21464605709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21464605769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10732302854 + 10732302855.

It is an arithmetic number, because the mean of its divisors is an integer number (10732302855).

Almost surely, 2^21464605709 is an apocalyptic number.

It is an amenable number.

21464605709 is a deficient number, since it is larger than the sum of its proper divisors (1).

21464605709 is an equidigital number, since it uses as much as digits as its factorization.

21464605709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 44.

The spelling of 21464605709 in words is "twenty-one billion, four hundred sixty-four million, six hundred five thousand, seven hundred nine".