21101311221 has 8 divisors (see below), whose sum is σ = 28135821120. Its totient is φ = 14067171072.

The previous prime is 21101311201. The next prime is 21101311241. The reversal of 21101311221 is 12211310112.

It is an interprime number because it is at equal distance from previous prime (21101311201) and next prime (21101311241).

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

It is not a de Polignac number, because 21101311221 - 2⁶ = 21101311157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21101311221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101311201) 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, 95056 + ... + 226358.

It is an arithmetic number, because the mean of its divisors is an integer number (3516977640).

Almost surely, 2^21101311221 is an apocalyptic number.

It is an amenable number.

21101311221 is a deficient number, since it is larger than the sum of its proper divisors (7034509899).

21101311221 is a wasteful number, since it uses less digits than its factorization.

21101311221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184875.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21101311221 its reverse (12211310112), we get a palindrome (33312621333).

The spelling of 21101311221 in words is "twenty-one billion, one hundred one million, three hundred eleven thousand, two hundred twenty-one".