64061686657 has 4 divisors (see below), whose sum is σ = 65270397780. Its totient is φ = 62852975536.

The previous prime is 64061686643. The next prime is 64061686673. The reversal of 64061686657 is 75668616046.

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

It can be written as a sum of positive squares in 2 ways, for example, as 32967301761 + 31094384896 = 181569^2 + 176336^2 .

It is a cyclic number.

It is not a de Polignac number, because 64061686657 - 2²⁷ = 63927468929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64061686598 and 64061686607.

It is not an unprimeable number, because it can be changed into a prime (64061686627) 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, 604355482 + ... + 604355587.

It is an arithmetic number, because the mean of its divisors is an integer number (16317599445).

Almost surely, 2^64061686657 is an apocalyptic number.

It is an amenable number.

64061686657 is a deficient number, since it is larger than the sum of its proper divisors (1208711123).

64061686657 is a wasteful number, since it uses less digits than its factorization.

64061686657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208711122.

The product of its (nonzero) digits is 8709120, while the sum is 55.

The spelling of 64061686657 in words is "sixty-four billion, sixty-one million, six hundred eighty-six thousand, six hundred fifty-seven".