21522267 has 32 divisors (see below), whose sum is σ = 34807360. Its totient is φ = 13226976.

The previous prime is 21522257. The next prime is 21522283. The reversal of 21522267 is 76222512.

It is not a de Polignac number, because 21522267 - 2⁴ = 21522251 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a nialpdrome in base 3 and base 9.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 21522267.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28053 + ... + 28809.

It is an arithmetic number, because the mean of its divisors is an integer number (1087730).

Almost surely, 2^21522267 is an apocalyptic number.

21522267 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21522267 is a deficient number, since it is larger than the sum of its proper divisors (13285093).

21522267 is an frugal number, since it uses more digits than its factorization.

21522267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791 (or 773 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21522267 is about 4639.2097387378. The cubic root of 21522267 is about 278.1608501025.

Adding to 21522267 its reverse (76222512), we get a palindrome (97744779).

The spelling of 21522267 in words is "twenty-one million, five hundred twenty-two thousand, two hundred sixty-seven".