64356393840 has 80 divisors (see below), whose sum is σ = 208178961408. Its totient is φ = 16415542528.

The previous prime is 64356393833. The next prime is 64356393887. The reversal of 64356393840 is 4839365346.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5823864 + ... + 5834903.

Almost surely, 2^64356393840 is an apocalyptic number.

64356393840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64356393840 is an abundant number, since it is smaller than the sum of its proper divisors (143822567568).

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

64356393840 is a wasteful number, since it uses less digits than its factorization.

64356393840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11658806 (or 11658800 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 51.

The spelling of 64356393840 in words is "sixty-four billion, three hundred fifty-six million, three hundred ninety-three thousand, eight hundred forty".