221620505 has 8 divisors (see below), whose sum is σ = 267577152. Its totient is φ = 176208048.

The previous prime is 221620501. The next prime is 221620543. The reversal of 221620505 is 505026122.

221620505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221620505 - 2² = 221620501 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221620501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135149 + ... + 136778.

It is an arithmetic number, because the mean of its divisors is an integer number (33447144).

Almost surely, 2^221620505 is an apocalyptic number.

It is an amenable number.

221620505 is a deficient number, since it is larger than the sum of its proper divisors (45956647).

221620505 is a wasteful number, since it uses less digits than its factorization.

221620505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272095.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 221620505 is about 14886.9239603083. The cubic root of 221620505 is about 605.1596737210.

Adding to 221620505 its reverse (505026122), we get a palindrome (726646627).

The spelling of 221620505 in words is "two hundred twenty-one million, six hundred twenty thousand, five hundred five".