21504525 has 24 divisors (see below), whose sum is σ = 40634304. Its totient is φ = 9830400.

The previous prime is 21504463. The next prime is 21504533. The reversal of 21504525 is 52540512.

It is a happy number.

It is not a de Polignac number, because 21504525 - 2⁷ = 21504397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21504495 and 21504504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19956 + ... + 21005.

It is an arithmetic number, because the mean of its divisors is an integer number (1693096).

Almost surely, 2^21504525 is an apocalyptic number.

21504525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21504525 is a deficient number, since it is larger than the sum of its proper divisors (19129779).

21504525 is a wasteful number, since it uses less digits than its factorization.

21504525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40981 (or 40976 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 21504525 is about 4637.2971653755. The cubic root of 21504525 is about 278.0843946107.

It can be divided in two parts, 21504 and 525, that multiplied together give a square (11289600 = 3360²).

The spelling of 21504525 in words is "twenty-one million, five hundred four thousand, five hundred twenty-five".