21071125 has 16 divisors (see below), whose sum is σ = 26573040. Its totient is φ = 16680000.

The previous prime is 21071123. The next prime is 21071137. The reversal of 21071125 is 52117012.

It can be written as a sum of positive squares in 8 ways, for example, as 1790244 + 19280881 = 1338^2 + 4391^2 .

It is not a de Polignac number, because 21071125 - 2¹ = 21071123 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21071123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11791 + ... + 13459.

It is an arithmetic number, because the mean of its divisors is an integer number (1660815).

Almost surely, 2^21071125 is an apocalyptic number.

21071125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21071125 is a deficient number, since it is larger than the sum of its proper divisors (5501915).

21071125 is a wasteful number, since it uses less digits than its factorization.

21071125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1785 (or 1775 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 21071125 is about 4590.3295088697. The cubic root of 21071125 is about 276.2035404353.

Adding to 21071125 its reverse (52117012), we get a palindrome (73188137).

The spelling of 21071125 in words is "twenty-one million, seventy-one thousand, one hundred twenty-five".