64644440626428 has 48 divisors (see below), whose sum is σ = 162740135210016. Its totient is φ = 19853830736640.

The previous prime is 64644440626421. The next prime is 64644440626457. The reversal of 64644440626428 is 82462604444646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64644440626421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 382898451 + ... + 383067242.

It is an arithmetic number, because the mean of its divisors is an integer number (3390419483542).

Almost surely, 2^{64644440626428} is an apocalyptic number.

It is an amenable number.

64644440626428 is an abundant number, since it is smaller than the sum of its proper divisors (98095694583588).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64644440626428 is a wasteful number, since it uses less digits than its factorization.

64644440626428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765966254 (or 765966252 counting only the distinct ones).

The product of its (nonzero) digits is 169869312, while the sum is 60.

The spelling of 64644440626428 in words is "sixty-four trillion, six hundred forty-four billion, four hundred forty million, six hundred twenty-six thousand, four hundred twenty-eight".