21080253 has 8 divisors (see below), whose sum is σ = 29586400. Its totient is φ = 13313808.

The previous prime is 21080249. The next prime is 21080261. The reversal of 21080253 is 35208012.

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

It is not a de Polignac number, because 21080253 - 2² = 21080249 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 (21080203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 184858 + ... + 184971.

It is an arithmetic number, because the mean of its divisors is an integer number (3698300).

Almost surely, 2^21080253 is an apocalyptic number.

It is an amenable number.

21080253 is a deficient number, since it is larger than the sum of its proper divisors (8506147).

21080253 is a wasteful number, since it uses less digits than its factorization.

21080253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369851.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21080253 is about 4591.3236653497. The cubic root of 21080253 is about 276.2434184191.

Adding to 21080253 its reverse (35208012), we get a palindrome (56288265).

The spelling of 21080253 in words is "twenty-one million, eighty thousand, two hundred fifty-three".