21146863 has 2 divisors, whose sum is σ = 21146864. Its totient is φ = 21146862.

The previous prime is 21146849. The next prime is 21146891. The reversal of 21146863 is 36864112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21146863 - 2⁵ = 21146831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21146803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10573431 + 10573432.

It is an arithmetic number, because the mean of its divisors is an integer number (10573432).

Almost surely, 2^21146863 is an apocalyptic number.

21146863 is a deficient number, since it is larger than the sum of its proper divisors (1).

21146863 is an equidigital number, since it uses as much as digits as its factorization.

21146863 is an evil number, because the sum of its binary digits is even.

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

The square root of 21146863 is about 4598.5718435184. The cubic root of 21146863 is about 276.5340731717.

It can be divided in two parts, 211 and 46863, that added together give a palindrome (47074).

The spelling of 21146863 in words is "twenty-one million, one hundred forty-six thousand, eight hundred sixty-three".