641620221 has 32 divisors (see below), whose sum is σ = 955584000. Its totient is φ = 379654080.

The previous prime is 641620211. The next prime is 641620223. The reversal of 641620221 is 122026146.

It is not a de Polignac number, because 641620221 - 2⁷ = 641620093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 641620191 and 641620200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641620223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 304630 + ... + 306728.

It is an arithmetic number, because the mean of its divisors is an integer number (29862000).

Almost surely, 2^641620221 is an apocalyptic number.

It is an amenable number.

641620221 is a deficient number, since it is larger than the sum of its proper divisors (313963779).

641620221 is a wasteful number, since it uses less digits than its factorization.

641620221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2329.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 641620221 is about 25330.2234692077. The cubic root of 641620221 is about 862.5004840997.

Adding to 641620221 its reverse (122026146), we get a palindrome (763646367).

The spelling of 641620221 in words is "six hundred forty-one million, six hundred twenty thousand, two hundred twenty-one".