21011325 has 24 divisors (see below), whose sum is σ = 34872768. Its totient is φ = 11162880.

The previous prime is 21011317. The next prime is 21011327. The reversal of 21011325 is 52311012.

It is not a de Polignac number, because 21011325 - 2³ = 21011317 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 not an unprimeable number, because it can be changed into a prime (21011327) 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, 32152 + ... + 32798.

It is an arithmetic number, because the mean of its divisors is an integer number (1453032).

Almost surely, 2^21011325 is an apocalyptic number.

21011325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21011325 is a deficient number, since it is larger than the sum of its proper divisors (13861443).

21011325 is a wasteful number, since it uses less digits than its factorization.

21011325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1093 (or 1088 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21011325 is about 4583.8111872109. The cubic root of 21011325 is about 275.9420036720.

Adding to 21011325 its reverse (52311012), we get a palindrome (73322337).

The spelling of 21011325 in words is "twenty-one million, eleven thousand, three hundred twenty-five".