21468631 has 4 divisors (see below), whose sum is σ = 21481200. Its totient is φ = 21456064.

The previous prime is 21468607. The next prime is 21468649. The reversal of 21468631 is 13686412.

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 21468631 - 2¹⁵ = 21435863 is a prime.

It is a super-2 number, since 2×21468631² = 921804234028322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 21468593 and 21468602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21468691) 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, 3226 + ... + 7303.

It is an arithmetic number, because the mean of its divisors is an integer number (5370300).

Almost surely, 2^21468631 is an apocalyptic number.

21468631 is a deficient number, since it is larger than the sum of its proper divisors (12569).

21468631 is a wasteful number, since it uses less digits than its factorization.

21468631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12568.

The product of its digits is 6912, while the sum is 31.

The square root of 21468631 is about 4633.4254067590. The cubic root of 21468631 is about 277.9295881231.

The spelling of 21468631 in words is "twenty-one million, four hundred sixty-eight thousand, six hundred thirty-one".