21254911 has 4 divisors (see below), whose sum is σ = 21395824. Its totient is φ = 21114000.

The previous prime is 21254903. The next prime is 21254923. The reversal of 21254911 is 11945212.

It is a happy number.

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 21254911 - 2³ = 21254903 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 (21254411) 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, 70230 + ... + 70531.

It is an arithmetic number, because the mean of its divisors is an integer number (5348956).

Almost surely, 2^21254911 is an apocalyptic number.

21254911 is a deficient number, since it is larger than the sum of its proper divisors (140913).

21254911 is a wasteful number, since it uses less digits than its factorization.

21254911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140912.

The product of its digits is 720, while the sum is 25.

The square root of 21254911 is about 4610.3048706132. The cubic root of 21254911 is about 277.0042486544.

The spelling of 21254911 in words is "twenty-one million, two hundred fifty-four thousand, nine hundred eleven".