64444105561 has 4 divisors (see below), whose sum is σ = 70302660624. Its totient is φ = 58585550500.

The previous prime is 64444105553. The next prime is 64444105603. The reversal of 64444105561 is 16550144446.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 64444105561 - 2³ = 64444105553 is a prime.

It is a super-2 number, since 2×64444105561² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64444105541) 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, 2929277515 + ... + 2929277536.

It is an arithmetic number, because the mean of its divisors is an integer number (17575665156).

Almost surely, 2^64444105561 is an apocalyptic number.

It is an amenable number.

64444105561 is a deficient number, since it is larger than the sum of its proper divisors (5858555063).

64444105561 is a wasteful number, since it uses less digits than its factorization.

64444105561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5858555062.

The product of its (nonzero) digits is 230400, while the sum is 40.

The spelling of 64444105561 in words is "sixty-four billion, four hundred forty-four million, one hundred five thousand, five hundred sixty-one".