64140517879 has 4 divisors (see below), whose sum is σ = 64263628800. Its totient is φ = 64017406960.

The previous prime is 64140517873. The next prime is 64140517891. The reversal of 64140517879 is 97871504146.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64140517879 - 2³ = 64140517871 is a prime.

It is a super-2 number, since 2×64140517879² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64140517871) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61554679 + ... + 61555720.

It is an arithmetic number, because the mean of its divisors is an integer number (16065907200).

Almost surely, 2^64140517879 is an apocalyptic number.

64140517879 is a deficient number, since it is larger than the sum of its proper divisors (123110921).

64140517879 is a wasteful number, since it uses less digits than its factorization.

64140517879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123110920.

The product of its (nonzero) digits is 1693440, while the sum is 52.

The spelling of 64140517879 in words is "sixty-four billion, one hundred forty million, five hundred seventeen thousand, eight hundred seventy-nine".