21466831 has 2 divisors, whose sum is σ = 21466832. Its totient is φ = 21466830.

The previous prime is 21466829. The next prime is 21466859. The reversal of 21466831 is 13866412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21466831 - 2¹ = 21466829 is a prime.

It is a super-2 number, since 2×21466831² = 921649666365122, which contains 22 as substring.

Together with 21466829, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1357645 and since 21466831 and 1357645 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 21466793 and 21466802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21461831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10733415 + 10733416.

It is an arithmetic number, because the mean of its divisors is an integer number (10733416).

Almost surely, 2^21466831 is an apocalyptic number.

21466831 is a deficient number, since it is larger than the sum of its proper divisors (1).

21466831 is an equidigital number, since it uses as much as digits as its factorization.

21466831 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21466831 is about 4633.2311619430. The cubic root of 21466831 is about 277.9218203985.

The spelling of 21466831 in words is "twenty-one million, four hundred sixty-six thousand, eight hundred thirty-one".