21112131 has 8 divisors (see below), whose sum is σ = 28428624. Its totient is φ = 13935200.

The previous prime is 21112127. The next prime is 21112139. The reversal of 21112131 is 13121112.

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 21112131 - 2² = 21112127 is a prime.

It is a super-2 number, since 2×21112131² = 891444150722322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21112139) 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, 34536 + ... + 35141.

It is an arithmetic number, because the mean of its divisors is an integer number (3553578).

Almost surely, 2^21112131 is an apocalyptic number.

21112131 is a deficient number, since it is larger than the sum of its proper divisors (7316493).

21112131 is a wasteful number, since it uses less digits than its factorization.

21112131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69781.

The product of its digits is 12, while the sum is 12.

The square root of 21112131 is about 4594.7939017980. The cubic root of 21112131 is about 276.3825953145.

Adding to 21112131 its reverse (13121112), we get a palindrome (34233243).

It can be divided in two parts, 21112 and 131, that multiplied together give a palindrome (2765672).

The spelling of 21112131 in words is "twenty-one million, one hundred twelve thousand, one hundred thirty-one".