21061325 has 12 divisors (see below), whose sum is σ = 26823060. Its totient is φ = 16392960.

The previous prime is 21061309. The next prime is 21061343. The reversal of 21061325 is 52316012.

It can be written as a sum of positive squares in 6 ways, for example, as 1249924 + 19811401 = 1118^2 + 4451^2 .

It is not a de Polignac number, because 21061325 - 2⁴ = 21061309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21061297 and 21061306.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10460 + ... + 12309.

It is an arithmetic number, because the mean of its divisors is an integer number (2235255).

Almost surely, 2^21061325 is an apocalyptic number.

21061325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21061325 is a deficient number, since it is larger than the sum of its proper divisors (5761735).

21061325 is a wasteful number, since it uses less digits than its factorization.

21061325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22816 (or 22811 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 21061325 is about 4589.2619232291. The cubic root of 21061325 is about 276.1607138272.

Adding to 21061325 its reverse (52316012), we get a palindrome (73377337).

The spelling of 21061325 in words is "twenty-one million, sixty-one thousand, three hundred twenty-five".