21254311 has 4 divisors (see below), whose sum is σ = 22889272. Its totient is φ = 19619352.

The previous prime is 21254309. The next prime is 21254327. The reversal of 21254311 is 11345212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21254311 - 2¹ = 21254309 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 (21254371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 817461 + ... + 817486.

It is an arithmetic number, because the mean of its divisors is an integer number (5722318).

Almost surely, 2^21254311 is an apocalyptic number.

21254311 is a deficient number, since it is larger than the sum of its proper divisors (1634961).

21254311 is a wasteful number, since it uses less digits than its factorization.

21254311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1634960.

The product of its digits is 240, while the sum is 19.

The square root of 21254311 is about 4610.2397985354. The cubic root of 21254311 is about 277.0016421334.

Adding to 21254311 its reverse (11345212), we get a palindrome (32599523).

Subtracting from 21254311 its reverse (11345212), we obtain a palindrome (9909099).

The spelling of 21254311 in words is "twenty-one million, two hundred fifty-four thousand, three hundred eleven".