21352111 has 4 divisors (see below), whose sum is σ = 23293224. Its totient is φ = 19411000.

The previous prime is 21352109. The next prime is 21352127. The reversal of 21352111 is 11125312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21352111 - 2¹ = 21352109 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 (21350111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 970540 + ... + 970561.

It is an arithmetic number, because the mean of its divisors is an integer number (5823306).

Almost surely, 2^21352111 is an apocalyptic number.

21352111 is the 2067-th centered decagonal number.

21352111 is a deficient number, since it is larger than the sum of its proper divisors (1941113).

21352111 is a wasteful number, since it uses less digits than its factorization.

21352111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1941112.

The product of its digits is 60, while the sum is 16.

The square root of 21352111 is about 4620.8344484519. The cubic root of 21352111 is about 277.4258590450.

Adding to 21352111 its reverse (11125312), we get a palindrome (32477423).

The spelling of 21352111 in words is "twenty-one million, three hundred fifty-two thousand, one hundred eleven".