21113075 has 6 divisors (see below), whose sum is σ = 26180244. Its totient is φ = 16890440.

The previous prime is 21113069. The next prime is 21113083. The reversal of 21113075 is 57031112.

It is not a de Polignac number, because 21113075 - 2¹⁶ = 21047539 is a prime.

It is a Duffinian number.

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 5 ways as a sum of consecutive naturals, for example, 422237 + ... + 422286.

It is an arithmetic number, because the mean of its divisors is an integer number (4363374).

Almost surely, 2^21113075 is an apocalyptic number.

21113075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21113075 is a deficient number, since it is larger than the sum of its proper divisors (5067169).

21113075 is an equidigital number, since it uses as much as digits as its factorization.

21113075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844533 (or 844528 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 21113075 is about 4594.8966256054. The cubic root of 21113075 is about 276.3867146094.

Adding to 21113075 its reverse (57031112), we get a palindrome (78144187).

The spelling of 21113075 in words is "twenty-one million, one hundred thirteen thousand, seventy-five".