64140251365 has 4 divisors (see below), whose sum is σ = 76968301644. Its totient is φ = 51312201088.

The previous prime is 64140251347. The next prime is 64140251389. The reversal of 64140251365 is 56315204146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56315204146 = 2 ⋅28157602073.

It can be written as a sum of positive squares in 2 ways, for example, as 42273827236 + 21866424129 = 205606^2 + 147873^2 .

It is a cyclic number.

It is not a de Polignac number, because 64140251365 - 2⁵ = 64140251333 is a prime.

It is a super-2 number, since 2×64140251365² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6414025132 + ... + 6414025141.

It is an arithmetic number, because the mean of its divisors is an integer number (19242075411).

Almost surely, 2^64140251365 is an apocalyptic number.

It is an amenable number.

64140251365 is a deficient number, since it is larger than the sum of its proper divisors (12828050279).

64140251365 is a wasteful number, since it uses less digits than its factorization.

64140251365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12828050278.

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 64140251365 in words is "sixty-four billion, one hundred forty million, two hundred fifty-one thousand, three hundred sixty-five".