21651322 has 16 divisors (see below), whose sum is σ = 40491072. Its totient is φ = 8435520.

The previous prime is 21651307. The next prime is 21651323. The reversal of 21651322 is 22315612.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21651293 and 21651302.

It is not an unprimeable number, because it can be changed into a prime (21651323) 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, 70143 + ... + 70450.

It is an arithmetic number, because the mean of its divisors is an integer number (2530692).

Almost surely, 2^21651322 is an apocalyptic number.

21651322 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21651322 is a deficient number, since it is larger than the sum of its proper divisors (18839750).

21651322 is a wasteful number, since it uses less digits than its factorization.

21651322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140613.

The product of its digits is 720, while the sum is 22.

The square root of 21651322 is about 4653.0981077128. The cubic root of 21651322 is about 278.7157255747.

Adding to 21651322 its reverse (22315612), we get a palindrome (43966934).

The spelling of 21651322 in words is "twenty-one million, six hundred fifty-one thousand, three hundred twenty-two".