64449090521 has 4 divisors (see below), whose sum is σ = 64459171812. Its totient is φ = 64439009232.

The previous prime is 64449090457. The next prime is 64449090577. The reversal of 64449090521 is 12509094446.

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 7750337296 + 56698753225 = 88036^2 + 238115^2 .

It is a cyclic number.

It is not a de Polignac number, because 64449090521 - 2⁶ = 64449090457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64449090721) 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, 5031050 + ... + 5043843.

It is an arithmetic number, because the mean of its divisors is an integer number (16114792953).

Almost surely, 2^64449090521 is an apocalyptic number.

It is an amenable number.

64449090521 is a deficient number, since it is larger than the sum of its proper divisors (10081291).

64449090521 is a wasteful number, since it uses less digits than its factorization.

64449090521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10081290.

The product of its (nonzero) digits is 311040, while the sum is 44.

The spelling of 64449090521 in words is "sixty-four billion, four hundred forty-nine million, ninety thousand, five hundred twenty-one".