21321021111 has 8 divisors (see below), whose sum is σ = 30614799600. Its totient is φ = 13120628352.

The previous prime is 21321021107. The next prime is 21321021131. The reversal of 21321021111 is 11112012312.

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

It is not a de Polignac number, because 21321021111 - 2² = 21321021107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321021131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273346386 + ... + 273346463.

It is an arithmetic number, because the mean of its divisors is an integer number (3826849950).

Almost surely, 2^21321021111 is an apocalyptic number.

21321021111 is a deficient number, since it is larger than the sum of its proper divisors (9293778489).

21321021111 is a wasteful number, since it uses less digits than its factorization.

21321021111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546692865.

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

Adding to 21321021111 its reverse (11112012312), we get a palindrome (32433033423).

The spelling of 21321021111 in words is "twenty-one billion, three hundred twenty-one million, twenty-one thousand, one hundred eleven".