21431322 has 48 divisors (see below), whose sum is σ = 53644032. Its totient is φ = 6111360.

The previous prime is 21431317. The next prime is 21431341. The reversal of 21431322 is 22313412.

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

It is a junction number, because it is equal to n+sod(n) for n = 21431295 and 21431304.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 183 + ... + 6549.

It is an arithmetic number, because the mean of its divisors is an integer number (1117584).

Almost surely, 2^21431322 is an apocalyptic number.

21431322 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21431322, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26822016).

21431322 is an abundant number, since it is smaller than the sum of its proper divisors (32212710).

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

21431322 is a wasteful number, since it uses less digits than its factorization.

21431322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6403 (or 6400 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 21431322 is about 4629.3975849996. The cubic root of 21431322 is about 277.7684959150.

Adding to 21431322 its reverse (22313412), we get a palindrome (43744734).

The spelling of 21431322 in words is "twenty-one million, four hundred thirty-one thousand, three hundred twenty-two".