64025136561 has 4 divisors (see below), whose sum is σ = 85366848752. Its totient is φ = 42683424372.

The previous prime is 64025136557. The next prime is 64025136569. The reversal of 64025136561 is 16563152046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 64025136561 - 2² = 64025136557 is a prime.

It is a super-2 number, since 2×64025136561² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64025136569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10670856091 + ... + 10670856096.

It is an arithmetic number, because the mean of its divisors is an integer number (21341712188).

Almost surely, 2^64025136561 is an apocalyptic number.

It is an amenable number.

64025136561 is a deficient number, since it is larger than the sum of its proper divisors (21341712191).

64025136561 is a wasteful number, since it uses less digits than its factorization.

64025136561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21341712190.

The product of its (nonzero) digits is 129600, while the sum is 39.

The spelling of 64025136561 in words is "sixty-four billion, twenty-five million, one hundred thirty-six thousand, five hundred sixty-one".