221215501 has 8 divisors (see below), whose sum is σ = 241103520. Its totient is φ = 201737712.

The previous prime is 221215493. The next prime is 221215507. The reversal of 221215501 is 105512122.

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 221215501 - 2³ = 221215493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221215507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101431 + ... + 103588.

It is an arithmetic number, because the mean of its divisors is an integer number (30137940).

Almost surely, 2^221215501 is an apocalyptic number.

It is an amenable number.

221215501 is a deficient number, since it is larger than the sum of its proper divisors (19888019).

221215501 is a wasteful number, since it uses less digits than its factorization.

221215501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205115.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 221215501 is about 14873.3150642350. The cubic root of 221215501 is about 604.7908126366.

Adding to 221215501 its reverse (105512122), we get a palindrome (326727623).

The spelling of 221215501 in words is "two hundred twenty-one million, two hundred fifteen thousand, five hundred one".