64563042721 has 4 divisors (see below), whose sum is σ = 64695616192. Its totient is φ = 64430469252.

The previous prime is 64563042689. The next prime is 64563042743. The reversal of 64563042721 is 12724036546.

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 64563042721 - 2⁵ = 64563042689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64563012721) 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, 66286005 + ... + 66286978.

It is an arithmetic number, because the mean of its divisors is an integer number (16173904048).

Almost surely, 2^64563042721 is an apocalyptic number.

It is an amenable number.

64563042721 is a deficient number, since it is larger than the sum of its proper divisors (132573471).

64563042721 is a wasteful number, since it uses less digits than its factorization.

64563042721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132573470.

The product of its (nonzero) digits is 241920, while the sum is 40.

The spelling of 64563042721 in words is "sixty-four billion, five hundred sixty-three million, forty-two thousand, seven hundred twenty-one".