21150354221 has 16 divisors (see below), whose sum is σ = 22007129088. Its totient is φ = 20304864000.

The previous prime is 21150354217. The next prime is 21150354227. The reversal of 21150354221 is 12245305112.

It is a cyclic number.

It is not a de Polignac number, because 21150354221 - 2² = 21150354217 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 (21150354227) 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, 3990245 + ... + 3995541.

It is an arithmetic number, because the mean of its divisors is an integer number (1375445568).

Almost surely, 2^21150354221 is an apocalyptic number.

It is an amenable number.

21150354221 is a deficient number, since it is larger than the sum of its proper divisors (856774867).

21150354221 is a wasteful number, since it uses less digits than its factorization.

21150354221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6332.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21150354221 its reverse (12245305112), we get a palindrome (33395659333).

The spelling of 21150354221 in words is "twenty-one billion, one hundred fifty million, three hundred fifty-four thousand, two hundred twenty-one".