21331101 has 8 divisors (see below), whose sum is σ = 31027104. Its totient is φ = 12927920.

The previous prime is 21331081. The next prime is 21331103. The reversal of 21331101 is 10113312.

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 21331101 - 2²² = 17136797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331103) 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, 323166 + ... + 323231.

It is an arithmetic number, because the mean of its divisors is an integer number (3878388).

Almost surely, 2^21331101 is an apocalyptic number.

It is an amenable number.

21331101 is a deficient number, since it is larger than the sum of its proper divisors (9696003).

21331101 is a wasteful number, since it uses less digits than its factorization.

21331101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646411.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 21331101 is about 4618.5604900228. The cubic root of 21331101 is about 277.3348355685.

Adding to 21331101 its reverse (10113312), we get a palindrome (31444413).

The spelling of 21331101 in words is "twenty-one million, three hundred thirty-one thousand, one hundred one".