21125372 has 24 divisors (see below), whose sum is σ = 38789184. Its totient is φ = 10055232.

The previous prime is 21125371. The next prime is 21125381. The reversal of 21125372 is 27352112.

It is a happy number.

It is a congruent number.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5438 + ... + 8474.

It is an arithmetic number, because the mean of its divisors is an integer number (1616216).

Almost surely, 2^21125372 is an apocalyptic number.

It is an amenable number.

21125372 is a deficient number, since it is larger than the sum of its proper divisors (17663812).

21125372 is a wasteful number, since it uses less digits than its factorization.

21125372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3125 (or 3123 counting only the distinct ones).

The product of its digits is 840, while the sum is 23.

The square root of 21125372 is about 4596.2345457994. The cubic root of 21125372 is about 276.4403633208.

Adding to 21125372 its reverse (27352112), we get a palindrome (48477484).

The spelling of 21125372 in words is "twenty-one million, one hundred twenty-five thousand, three hundred seventy-two".