21161325 has 24 divisors (see below), whose sum is σ = 35145568. Its totient is φ = 11234880.

The previous prime is 21161323. The next prime is 21161377. The reversal of 21161325 is 52316112.

It is not a de Polignac number, because 21161325 - 2¹ = 21161323 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161321) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 20727 + ... + 21723.

Almost surely, 2^21161325 is an apocalyptic number.

21161325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21161325 is a deficient number, since it is larger than the sum of its proper divisors (13984243).

21161325 is a wasteful number, since it uses less digits than its factorization.

21161325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1293 (or 1288 counting only the distinct ones).

The product of its digits is 360, while the sum is 21.

The square root of 21161325 is about 4600.1440194846. The cubic root of 21161325 is about 276.5970978773.

Adding to 21161325 its reverse (52316112), we get a palindrome (73477437).

The spelling of 21161325 in words is "twenty-one million, one hundred sixty-one thousand, three hundred twenty-five".