21254261 has 8 divisors (see below), whose sum is σ = 24432384. Its totient is φ = 18111600.

The previous prime is 21254249. The next prime is 21254263. The reversal of 21254261 is 16245212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21254261 - 2¹⁰ = 21253237 is a prime.

It is a super-2 number, since 2×21254261² = 903487221312242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254263) 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, 7565 + ... + 9986.

It is an arithmetic number, because the mean of its divisors is an integer number (3054048).

Almost surely, 2^21254261 is an apocalyptic number.

It is an amenable number.

21254261 is a deficient number, since it is larger than the sum of its proper divisors (3178123).

21254261 is a wasteful number, since it uses less digits than its factorization.

21254261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17731.

The product of its digits is 960, while the sum is 23.

The square root of 21254261 is about 4610.2343758208. The cubic root of 21254261 is about 277.0014249211.

Adding to 21254261 its reverse (16245212), we get a palindrome (37499473).

The spelling of 21254261 in words is "twenty-one million, two hundred fifty-four thousand, two hundred sixty-one".