21125264 has 20 divisors (see below), whose sum is σ = 43085040. Its totient is φ = 10006560.

The previous prime is 21125257. The next prime is 21125267. The reversal of 21125264 is 46252112.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21125267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34442 + ... + 35049.

It is an arithmetic number, because the mean of its divisors is an integer number (2154252).

Almost surely, 2^21125264 is an apocalyptic number.

It is an amenable number.

21125264 is an abundant number, since it is smaller than the sum of its proper divisors (21959776).

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

21125264 is a wasteful number, since it uses less digits than its factorization.

21125264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69518 (or 69512 counting only the distinct ones).

The product of its digits is 960, while the sum is 23.

The square root of 21125264 is about 4596.2227970367. Note that the first 3 decimals coincide. The cubic root of 21125264 is about 276.4398922346.

Adding to 21125264 its reverse (46252112), we get a palindrome (67377376).

The spelling of 21125264 in words is "twenty-one million, one hundred twenty-five thousand, two hundred sixty-four".