64203626821 has 2 divisors, whose sum is σ = 64203626822. Its totient is φ = 64203626820.

The previous prime is 64203626779. The next prime is 64203626867. The reversal of 64203626821 is 12862630246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63787058721 + 416568100 = 252561^2 + 20410^2 .

It is a cyclic number.

It is not a de Polignac number, because 64203626821 - 2⁹ = 64203626309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64203626881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32101813410 + 32101813411.

It is an arithmetic number, because the mean of its divisors is an integer number (32101813411).

Almost surely, 2^64203626821 is an apocalyptic number.

It is an amenable number.

64203626821 is a deficient number, since it is larger than the sum of its proper divisors (1).

64203626821 is an equidigital number, since it uses as much as digits as its factorization.

64203626821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 40.

The spelling of 64203626821 in words is "sixty-four billion, two hundred three million, six hundred twenty-six thousand, eight hundred twenty-one".