21345546 has 16 divisors (see below), whose sum is σ = 44068608. Its totient is φ = 6885600.

The previous prime is 21345539. The next prime is 21345589. The reversal of 21345546 is 64554312.

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 7 ways as a sum of consecutive naturals, for example, 57195 + ... + 57566.

It is an arithmetic number, because the mean of its divisors is an integer number (2754288).

Almost surely, 2^21345546 is an apocalyptic number.

21345546 is an abundant number, since it is smaller than the sum of its proper divisors (22723062).

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

21345546 is a wasteful number, since it uses less digits than its factorization.

21345546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114797.

The product of its digits is 14400, while the sum is 30.

The square root of 21345546 is about 4620.1240243093. The cubic root of 21345546 is about 277.3974233327.

Adding to 21345546 its reverse (64554312), we get a palindrome (85899858).

The spelling of 21345546 in words is "twenty-one million, three hundred forty-five thousand, five hundred forty-six".