64644440626457 has 2 divisors, whose sum is σ = 64644440626458. Its totient is φ = 64644440626456.

The previous prime is 64644440626421. The next prime is 64644440626459. The reversal of 64644440626457 is 75462604444646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64489315714576 + 155124911881 = 8030524^2 + 393859^2 .

It is a cyclic number.

It is not a de Polignac number, because 64644440626457 - 2⁸ = 64644440626201 is a prime.

Together with 64644440626459, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 64644440626457.

It is not a weakly prime, because it can be changed into another prime (64644440626459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32322220313228 + 32322220313229.

It is an arithmetic number, because the mean of its divisors is an integer number (32322220313229).

Almost surely, 2^{64644440626457} is an apocalyptic number.

It is an amenable number.

64644440626457 is a deficient number, since it is larger than the sum of its proper divisors (1).

64644440626457 is an equidigital number, since it uses as much as digits as its factorization.

64644440626457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 371589120, while the sum is 62.

The spelling of 64644440626457 in words is "sixty-four trillion, six hundred forty-four billion, four hundred forty million, six hundred twenty-six thousand, four hundred fifty-seven".