21436231 has 8 divisors (see below), whose sum is σ = 22238480. Its totient is φ = 20647872.

The previous prime is 21436229. The next prime is 21436241. The reversal of 21436231 is 13263412.

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 21436231 - 2¹ = 21436229 is a prime.

It is a super-2 number, since 2×21436231² = 919023998970722, 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 (21436241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 276 + ... + 6553.

It is an arithmetic number, because the mean of its divisors is an integer number (2779810).

Almost surely, 2^21436231 is an apocalyptic number.

21436231 is a deficient number, since it is larger than the sum of its proper divisors (802249).

21436231 is an equidigital number, since it uses as much as digits as its factorization.

21436231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6945.

The product of its digits is 864, while the sum is 22.

The square root of 21436231 is about 4629.9277532160. The cubic root of 21436231 is about 277.7897025933.

Adding to 21436231 its reverse (13263412), we get a palindrome (34699643).

The spelling of 21436231 in words is "twenty-one million, four hundred thirty-six thousand, two hundred thirty-one".