3664615221 has 6 divisors (see below), whose sum is σ = 5293333110. Its totient is φ = 2443076808.

The previous prime is 3664615211. The next prime is 3664615223. The reversal of 3664615221 is 1225164663.

3664615221 is a `hidden beast` number, since 3 + 6 + 646 + 1 + 5 + 2 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2193048900 + 1471566321 = 46830^2 + 38361^2 .

It is not a de Polignac number, because 3664615221 - 2²² = 3660420917 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3664615223) 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 5 ways as a sum of consecutive naturals, for example, 203589726 + ... + 203589743.

It is an arithmetic number, because the mean of its divisors is an integer number (882222185).

Almost surely, 2^3664615221 is an apocalyptic number.

It is an amenable number.

3664615221 is a deficient number, since it is larger than the sum of its proper divisors (1628717889).

3664615221 is a wasteful number, since it uses less digits than its factorization.

3664615221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407179475 (or 407179472 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 3664615221 is about 60536.0654568828. The cubic root of 3664615221 is about 1541.7340366540.

Adding to 3664615221 its reverse (1225164663), we get a palindrome (4889779884).

The spelling of 3664615221 in words is "three billion, six hundred sixty-four million, six hundred fifteen thousand, two hundred twenty-one".