21142125 has 24 divisors (see below), whose sum is σ = 38114232. Its totient is φ = 11275200.

The previous prime is 21142123. The next prime is 21142127. The reversal of 21142125 is 52124112.

It is an interprime number because it is at equal distance from previous prime (21142123) and next prime (21142127).

It can be written as a sum of positive squares in 4 ways, for example, as 184041 + 20958084 = 429^2 + 4578^2 .

It is not a de Polignac number, because 21142125 - 2¹ = 21142123 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21142098 and 21142107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8272 + ... + 10521.

It is an arithmetic number, because the mean of its divisors is an integer number (1588093).

Almost surely, 2^21142125 is an apocalyptic number.

21142125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21142125 is a deficient number, since it is larger than the sum of its proper divisors (16972107).

21142125 is a wasteful number, since it uses less digits than its factorization.

21142125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18814 (or 18801 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 21142125 is about 4598.0566547184. The cubic root of 21142125 is about 276.5134189451.

Adding to 21142125 its reverse (52124112), we get a palindrome (73266237).

The spelling of 21142125 in words is "twenty-one million, one hundred forty-two thousand, one hundred twenty-five".