64099556561 has 4 divisors (see below), whose sum is σ = 66167284224. Its totient is φ = 62031828900.

The previous prime is 64099556537. The next prime is 64099556629. The reversal of 64099556561 is 16565599046.

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 64099556561 - 2¹⁰ = 64099555537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64099556497 and 64099556506.

It is not an unprimeable number, because it can be changed into a prime (64099556501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1033863785 + ... + 1033863846.

It is an arithmetic number, because the mean of its divisors is an integer number (16541821056).

Almost surely, 2^64099556561 is an apocalyptic number.

It is an amenable number.

64099556561 is a deficient number, since it is larger than the sum of its proper divisors (2067727663).

64099556561 is a wasteful number, since it uses less digits than its factorization.

64099556561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2067727662.

The product of its (nonzero) digits is 8748000, while the sum is 56.

The spelling of 64099556561 in words is "sixty-four billion, ninety-nine million, five hundred fifty-six thousand, five hundred sixty-one".