21234261 has 8 divisors (see below), whose sum is σ = 28437984. Its totient is φ = 14093360.

The previous prime is 21234211. The next prime is 21234281. The reversal of 21234261 is 16243212.

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 21234261 - 2¹⁷ = 21103189 is a prime.

It is a super-2 number, since 2×21234261² = 901787680432242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234211) 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, 14910 + ... + 16271.

It is an arithmetic number, because the mean of its divisors is an integer number (3554748).

Almost surely, 2^21234261 is an apocalyptic number.

It is an amenable number.

21234261 is a deficient number, since it is larger than the sum of its proper divisors (7203723).

21234261 is a wasteful number, since it uses less digits than its factorization.

21234261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31411.

The product of its digits is 576, while the sum is 21.

The square root of 21234261 is about 4608.0647781905. The cubic root of 21234261 is about 276.9145126684.

Adding to 21234261 its reverse (16243212), we get a palindrome (37477473).

The spelling of 21234261 in words is "twenty-one million, two hundred thirty-four thousand, two hundred sixty-one".