64405629128 has 8 divisors (see below), whose sum is σ = 120760554630. Its totient is φ = 32202814560.

The previous prime is 64405629121. The next prime is 64405629133. The reversal of 64405629128 is 82192650446.

It can be written as a sum of positive squares in only one way, i.e., 59038308484 + 5367320644 = 242978^2 + 73262^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (64405629121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4025351813 + ... + 4025351828.

Almost surely, 2^64405629128 is an apocalyptic number.

It is an amenable number.

64405629128 is a deficient number, since it is larger than the sum of its proper divisors (56354925502).

64405629128 is a wasteful number, since it uses less digits than its factorization.

64405629128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8050703647 (or 8050703643 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 47.

The spelling of 64405629128 in words is "sixty-four billion, four hundred five million, six hundred twenty-nine thousand, one hundred twenty-eight".