3621557664 has 36 divisors (see below), whose sum is σ = 10298805426. Its totient is φ = 1207185792.

The previous prime is 3621557663. The next prime is 3621557689. The reversal of 3621557664 is 4667551263.

3621557664 is a `hidden beast` number, since 3 + 6 + 2 + 15 + 576 + 64 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2863106064 + 758451600 = 53508^2 + 27540^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (3621557663) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 6287139 + ... + 6287714.

Almost surely, 2^3621557664 is an apocalyptic number.

It is an amenable number.

3621557664 is an abundant number, since it is smaller than the sum of its proper divisors (6677247762).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3621557664 is a wasteful number, since it uses less digits than its factorization.

3621557664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12574869 (or 12574858 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The square root of 3621557664 is about 60179.3790596081. The cubic root of 3621557664 is about 1535.6720084174.

The spelling of 3621557664 in words is "three billion, six hundred twenty-one million, five hundred fifty-seven thousand, six hundred sixty-four".