2581521064 has 16 divisors (see below), whose sum is σ = 4853334420. Its totient is φ = 1287298560.

The previous prime is 2581521049. The next prime is 2581521091. The reversal of 2581521064 is 4601251852.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2566232964 + 15288100 = 50658^2 + 3910^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 429577 + ... + 435544.

Almost surely, 2^2581521064 is an apocalyptic number.

It is an amenable number.

2581521064 is a deficient number, since it is larger than the sum of its proper divisors (2271813356).

2581521064 is a wasteful number, since it uses less digits than its factorization.

2581521064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865500 (or 865496 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 2581521064 is about 50808.6711497162. The cubic root of 2581521064 is about 1371.8034508368.

The spelling of 2581521064 in words is "two billion, five hundred eighty-one million, five hundred twenty-one thousand, sixty-four".