64635613421 has 2 divisors, whose sum is σ = 64635613422. Its totient is φ = 64635613420.

The previous prime is 64635613379. The next prime is 64635613451. The reversal of 64635613421 is 12431653646.

64635613421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60619856521 + 4015756900 = 246211^2 + 63370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64635613421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64635613451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32317806710 + 32317806711.

It is an arithmetic number, because the mean of its divisors is an integer number (32317806711).

Almost surely, 2^64635613421 is an apocalyptic number.

It is an amenable number.

64635613421 is a deficient number, since it is larger than the sum of its proper divisors (1).

64635613421 is an equidigital number, since it uses as much as digits as its factorization.

64635613421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311040, while the sum is 41.

The spelling of 64635613421 in words is "sixty-four billion, six hundred thirty-five million, six hundred thirteen thousand, four hundred twenty-one".