21594253 has 2 divisors, whose sum is σ = 21594254. Its totient is φ = 21594252.

The previous prime is 21594247. The next prime is 21594277. The reversal of 21594253 is 35249512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18507204 + 3087049 = 4302^2 + 1757^2 .

It is a cyclic number.

It is not a de Polignac number, because 21594253 - 2¹⁷ = 21463181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21594553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10797126 + 10797127.

It is an arithmetic number, because the mean of its divisors is an integer number (10797127).

Almost surely, 2^21594253 is an apocalyptic number.

It is an amenable number.

21594253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21594253 is an equidigital number, since it uses as much as digits as its factorization.

21594253 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10800, while the sum is 31.

The square root of 21594253 is about 4646.9616955598. The cubic root of 21594253 is about 278.4706285564.

The spelling of 21594253 in words is "twenty-one million, five hundred ninety-four thousand, two hundred fifty-three".