21464604641 has 2 divisors, whose sum is σ = 21464604642. Its totient is φ = 21464604640.

The previous prime is 21464604559. The next prime is 21464604643. The reversal of 21464604641 is 14640646412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16590470416 + 4874134225 = 128804^2 + 69815^2 .

It is a cyclic number.

It is not a de Polignac number, because 21464604641 - 2¹⁰ = 21464603617 is a prime.

Together with 21464604643, 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 = 21464604595 and 21464604604.

It is not a weakly prime, because it can be changed into another prime (21464604643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10732302320 + 10732302321.

It is an arithmetic number, because the mean of its divisors is an integer number (10732302321).

Almost surely, 2^21464604641 is an apocalyptic number.

It is an amenable number.

21464604641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21464604641 is an equidigital number, since it uses as much as digits as its factorization.

21464604641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 110592, while the sum is 38.

The spelling of 21464604641 in words is "twenty-one billion, four hundred sixty-four million, six hundred four thousand, six hundred forty-one".