21466631 has 6 divisors (see below), whose sum is σ = 22803960. Its totient is φ = 20203616.

The previous prime is 21466609. The next prime is 21466633. The reversal of 21466631 is 13666412.

It is a happy number.

It is not a de Polignac number, because 21466631 - 2¹⁸ = 21204487 is a prime.

It is a super-2 number, since 2×21466631² = 921632492980322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21466594 and 21466603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21466633) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36851 + ... + 37428.

It is an arithmetic number, because the mean of its divisors is an integer number (3800660).

Almost surely, 2^21466631 is an apocalyptic number.

21466631 is a deficient number, since it is larger than the sum of its proper divisors (1337329).

21466631 is an equidigital number, since it uses as much as digits as its factorization.

21466631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74313 (or 74296 counting only the distinct ones).

The product of its digits is 5184, while the sum is 29.

The square root of 21466631 is about 4633.2095786830. The cubic root of 21466631 is about 277.9209572912.

The spelling of 21466631 in words is "twenty-one million, four hundred sixty-six thousand, six hundred thirty-one".