221620641 has 16 divisors (see below), whose sum is σ = 322648320. Its totient is φ = 134194320.

The previous prime is 221620603. The next prime is 221620649. The reversal of 221620641 is 146026122.

221620641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221620641 - 2⁶ = 221620577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221620649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45846 + ... + 50448.

It is an arithmetic number, because the mean of its divisors is an integer number (20165520).

Almost surely, 2^221620641 is an apocalyptic number.

It is an amenable number.

221620641 is a deficient number, since it is larger than the sum of its proper divisors (101027679).

221620641 is a wasteful number, since it uses less digits than its factorization.

221620641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6076.

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

The square root of 221620641 is about 14886.9285280746. The cubic root of 221620641 is about 605.1597975088.

Adding to 221620641 its reverse (146026122), we get a palindrome (367646763).

The spelling of 221620641 in words is "two hundred twenty-one million, six hundred twenty thousand, six hundred forty-one".