21580253 has 8 divisors (see below), whose sum is σ = 22020000. Its totient is φ = 21143088.

The previous prime is 21580243. The next prime is 21580267. The reversal of 21580253 is 35208512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21580253 - 2⁶ = 21580189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21580243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29075 + ... + 29807.

It is an arithmetic number, because the mean of its divisors is an integer number (2752500).

Almost surely, 2^21580253 is an apocalyptic number.

It is an amenable number.

21580253 is a deficient number, since it is larger than the sum of its proper divisors (439747).

21580253 is an equidigital number, since it uses as much as digits as its factorization.

21580253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1291.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 21580253 is about 4645.4550907312. The cubic root of 21580253 is about 278.4104361275.

Adding to 21580253 its reverse (35208512), we get a palindrome (56788765).

The spelling of 21580253 in words is "twenty-one million, five hundred eighty thousand, two hundred fifty-three".