21140825 has 12 divisors (see below), whose sum is σ = 27594960. Its totient is φ = 16022160.

The previous prime is 21140813. The next prime is 21140827. The reversal of 21140825 is 52804112.

It is not a de Polignac number, because 21140825 - 2⁸ = 21140569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21140825.

It is not an unprimeable number, because it can be changed into a prime (21140827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21779 + ... + 22728.

It is an arithmetic number, because the mean of its divisors is an integer number (2299580).

Almost surely, 2^21140825 is an apocalyptic number.

21140825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21140825 is a deficient number, since it is larger than the sum of its proper divisors (6454135).

21140825 is a wasteful number, since it uses less digits than its factorization.

21140825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44536 (or 44531 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 21140825 is about 4597.9152884759. The cubic root of 21140825 is about 276.5077513531.

Adding to 21140825 its reverse (52804112), we get a palindrome (73944937).

The spelling of 21140825 in words is "twenty-one million, one hundred forty thousand, eight hundred twenty-five".