21345522 has 32 divisors (see below), whose sum is σ = 47836224. Its totient is φ = 6292800.

The previous prime is 21345521. The next prime is 21345539. The reversal of 21345522 is 22554312.

It is a junction number, because it is equal to n+sod(n) for n = 21345492 and 21345501.

It is not an unprimeable number, because it can be changed into a prime (21345521) 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 15 ways as a sum of consecutive naturals, for example, 1929 + ... + 6812.

It is an arithmetic number, because the mean of its divisors is an integer number (1494882).

Almost surely, 2^21345522 is an apocalyptic number.

21345522 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21345522 is an abundant number, since it is smaller than the sum of its proper divisors (26490702).

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

21345522 is a wasteful number, since it uses less digits than its factorization.

21345522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8794.

The product of its digits is 2400, while the sum is 24.

The square root of 21345522 is about 4620.1214269757. The cubic root of 21345522 is about 277.3973193681.

Adding to 21345522 its reverse (22554312), we get a palindrome (43899834).

It can be divided in two parts, 21 and 345522, that added together give a palindrome (345543).

The spelling of 21345522 in words is "twenty-one million, three hundred forty-five thousand, five hundred twenty-two".