21260075 has 6 divisors (see below), whose sum is σ = 26362524. Its totient is φ = 17008040.

The previous prime is 21260051. The next prime is 21260077. The reversal of 21260075 is 57006212.

It is not a de Polignac number, because 21260075 - 2⁶ = 21260011 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21260075.

It is not an unprimeable number, because it can be changed into a prime (21260077) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 425177 + ... + 425226.

It is an arithmetic number, because the mean of its divisors is an integer number (4393754).

Almost surely, 2^21260075 is an apocalyptic number.

21260075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21260075 is a deficient number, since it is larger than the sum of its proper divisors (5102449).

21260075 is an equidigital number, since it uses as much as digits as its factorization.

21260075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850413 (or 850408 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21260075 is about 4610.8648863310. The cubic root of 21260075 is about 277.0266800838.

Adding to 21260075 its reverse (57006212), we get a palindrome (78266287).

The spelling of 21260075 in words is "twenty-one million, two hundred sixty thousand, seventy-five".