21529125 has 32 divisors (see below), whose sum is σ = 39811200. Its totient is φ = 11480400.

The previous prime is 21529093. The next prime is 21529129. The reversal of 21529125 is 52192512.

21529125 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 21529125 - 2⁵ = 21529093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21529129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186 + ... + 6564.

It is an arithmetic number, because the mean of its divisors is an integer number (1244100).

Almost surely, 2^21529125 is an apocalyptic number.

21529125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21529125 is a deficient number, since it is larger than the sum of its proper divisors (18282075).

21529125 is an equidigital number, since it uses as much as digits as its factorization.

21529125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6403 (or 6387 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 21529125 is about 4639.9488143728. The cubic root of 21529125 is about 278.1903919800.

The spelling of 21529125 in words is "twenty-one million, five hundred twenty-nine thousand, one hundred twenty-five".