21125376 has 108 divisors (see below), whose sum is σ = 62417628. Its totient is φ = 6868992.

The previous prime is 21125371. The next prime is 21125381. The reversal of 21125376 is 67352112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21125371) and next prime (21125381).

It can be written as a sum of positive squares in 2 ways, for example, as 17438976 + 3686400 = 4176^2 + 1920^2 .

It is a super-2 number, since 2×21125376² = 892563022282752, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21125371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122026 + ... + 122198.

It is an arithmetic number, because the mean of its divisors is an integer number (577941).

Almost surely, 2^21125376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21125376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31208814).

21125376 is an abundant number, since it is smaller than the sum of its proper divisors (41292252).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21125376 is a wasteful number, since it uses less digits than its factorization.

21125376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 231 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 21125376 is about 4596.2349809382. The cubic root of 21125376 is about 276.4403807684.

Adding to 21125376 its reverse (67352112), we get a palindrome (88477488).

The spelling of 21125376 in words is "twenty-one million, one hundred twenty-five thousand, three hundred seventy-six".