21225075 has 12 divisors (see below), whose sum is σ = 35092248. Its totient is φ = 11320000.

The previous prime is 21225047. The next prime is 21225077. The reversal of 21225075 is 57052212.

It is not a de Polignac number, because 21225075 - 2⁹ = 21224563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21225077) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141426 + ... + 141575.

It is an arithmetic number, because the mean of its divisors is an integer number (2924354).

Almost surely, 2^21225075 is an apocalyptic number.

21225075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21225075 is a deficient number, since it is larger than the sum of its proper divisors (13867173).

21225075 is a wasteful number, since it uses less digits than its factorization.

21225075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283014 (or 283009 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 21225075 is about 4607.0679395902. The cubic root of 21225075 is about 276.8745755811.

Adding to 21225075 its reverse (57052212), we get a palindrome (78277287).

The spelling of 21225075 in words is "twenty-one million, two hundred twenty-five thousand, seventy-five".