641321636 has 6 divisors (see below), whose sum is σ = 1122312870. Its totient is φ = 320660816.

The previous prime is 641321633. The next prime is 641321647. The reversal of 641321636 is 636123146.

It can be written as a sum of positive squares in only one way, i.e., 321126400 + 320195236 = 17920^2 + 17894^2 .

It is a super-2 number, since 2×641321636² = 822586881603432992, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (641321633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80165201 + ... + 80165208.

It is an arithmetic number, because the mean of its divisors is an integer number (187052145).

Almost surely, 2^641321636 is an apocalyptic number.

It is an amenable number.

641321636 is a deficient number, since it is larger than the sum of its proper divisors (480991234).

641321636 is a wasteful number, since it uses less digits than its factorization.

641321636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160330413 (or 160330411 counting only the distinct ones).

The product of its digits is 15552, while the sum is 32.

The square root of 641321636 is about 25324.3289348405. The cubic root of 641321636 is about 862.3666719904.

The spelling of 641321636 in words is "six hundred forty-one million, three hundred twenty-one thousand, six hundred thirty-six".