21582253 has 16 divisors (see below), whose sum is σ = 27131904. Its totient is φ = 16677360.

The previous prime is 21582251. The next prime is 21582263. The reversal of 21582253 is 35228512.

It is not a de Polignac number, because 21582253 - 2¹ = 21582251 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 (21582251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8676 + ... + 10882.

It is an arithmetic number, because the mean of its divisors is an integer number (1695744).

Almost surely, 2^21582253 is an apocalyptic number.

It is an amenable number.

21582253 is a deficient number, since it is larger than the sum of its proper divisors (5549651).

21582253 is a wasteful number, since it uses less digits than its factorization.

21582253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2352.

The product of its digits is 4800, while the sum is 28.

The square root of 21582253 is about 4645.6703499065. The cubic root of 21582253 is about 278.4190366395.

The spelling of 21582253 in words is "twenty-one million, five hundred eighty-two thousand, two hundred fifty-three".