21623112 has 144 divisors (see below), whose sum is σ = 70958160. Its totient is φ = 6150816.

The previous prime is 21623101. The next prime is 21623131. The reversal of 21623112 is 21132612.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 95143 + ... + 95369.

It is an arithmetic number, because the mean of its divisors is an integer number (492765).

Almost surely, 2^21623112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21623112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35479080).

21623112 is an abundant number, since it is smaller than the sum of its proper divisors (49335048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21623112 is a wasteful number, since it uses less digits than its factorization.

21623112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262 (or 239 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 21623112 is about 4650.0658059860. The cubic root of 21623112 is about 278.5946246112.

Adding to 21623112 its reverse (21132612), we get a palindrome (42755724).

The spelling of 21623112 in words is "twenty-one million, six hundred twenty-three thousand, one hundred twelve".