21211125 has 64 divisors (see below), whose sum is σ = 40185600. Its totient is φ = 9849600.

The previous prime is 21211109. The next prime is 21211139. The reversal of 21211125 is 52111212.

It is not a de Polignac number, because 21211125 - 2⁴ = 21211109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 92511 + ... + 92739.

It is an arithmetic number, because the mean of its divisors is an integer number (627900).

Almost surely, 2^21211125 is an apocalyptic number.

21211125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21211125 is a deficient number, since it is larger than the sum of its proper divisors (18974475).

21211125 is a wasteful number, since it uses less digits than its factorization.

21211125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279 (or 269 counting only the distinct ones).

The product of its digits is 40, while the sum is 15.

The square root of 21211125 is about 4605.5537126387. The cubic root of 21211125 is about 276.8139044674.

Adding to 21211125 its reverse (52111212), we get a palindrome (73322337).

The spelling of 21211125 in words is "twenty-one million, two hundred eleven thousand, one hundred twenty-five".