21454525 has 12 divisors (see below), whose sum is σ = 26810784. Its totient is φ = 17030000.

The previous prime is 21454483. The next prime is 21454541. The reversal of 21454525 is 52545412.

21454525 is a nontrivial binomial coefficient, being equal to C(6551, 2).

It is not a de Polignac number, because 21454525 - 2⁷ = 21454397 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21454493 and 21454502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1 + ... + 6550.

It is an arithmetic number, because the mean of its divisors is an integer number (2234232).

Almost surely, 2^21454525 is an apocalyptic number.

21454525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21454525 is the 6550-th triangular number.

21454525 is the 2184-th centered nonagonal number.

It is an amenable number.

21454525 is a deficient number, since it is larger than the sum of its proper divisors (5356259).

21454525 is a wasteful number, since it uses less digits than its factorization.

21454525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6692 (or 6687 counting only the distinct ones).

The product of its digits is 8000, while the sum is 28.

The square root of 21454525 is about 4631.9029566691. The cubic root of 21454525 is about 277.8687034190.

Adding to 21454525 its reverse (52545412), we get a palindrome (73999937).

It can be divided in two parts, 2145 and 4525, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 21454525 in words is "twenty-one million, four hundred fifty-four thousand, five hundred twenty-five".