64496189521 has 9 divisors (see below), whose sum is σ = 64837526961. Its totient is φ = 64156643664.

The previous prime is 64496189503. The next prime is 64496189581. The reversal of 64496189521 is 12598169446.

The square root of 64496189521 is 253961.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1213755921 + 63282433600 = 34839^2 + 251560^2 .

It is not a de Polignac number, because 64496189521 - 2¹⁷ = 64496058449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64496189581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 58156515 + ... + 58157623.

Almost surely, 2^64496189521 is an apocalyptic number.

64496189521 is the 253961-st square number.

64496189521 is the 126981-st centered octagonal number.

It is an amenable number.

64496189521 is a deficient number, since it is larger than the sum of its proper divisors (341337440).

64496189521 is an frugal number, since it uses more digits than its factorization.

64496189521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2676 (or 1338 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 55.

The spelling of 64496189521 in words is "sixty-four billion, four hundred ninety-six million, one hundred eighty-nine thousand, five hundred twenty-one".