21263625 has 48 divisors (see below), whose sum is σ = 39351312. Its totient is φ = 11040000.

The previous prime is 21263623. The next prime is 21263647. The reversal of 21263625 is 52636212.

21263625 is a `hidden beast` number, since 2 + 1 + 2 + 636 + 25 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 14653584 + 6610041 = 3828^2 + 2571^2 .

It is not a de Polignac number, because 21263625 - 2¹ = 21263623 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21263621) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 45895 + ... + 46355.

It is an arithmetic number, because the mean of its divisors is an integer number (819819).

Almost surely, 2^21263625 is an apocalyptic number.

21263625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21263625 is a deficient number, since it is larger than the sum of its proper divisors (18087687).

21263625 is a wasteful number, since it uses less digits than its factorization.

21263625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 510 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 21263625 is about 4611.2498305774. The cubic root of 21263625 is about 277.0420984989.

Adding to 21263625 its reverse (52636212), we get a palindrome (73899837).

The spelling of 21263625 in words is "twenty-one million, two hundred sixty-three thousand, six hundred twenty-five".