21463447 has 2 divisors, whose sum is σ = 21463448. Its totient is φ = 21463446.

The previous prime is 21463427. The next prime is 21463489. The reversal of 21463447 is 74436412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21463447 - 2¹¹ = 21461399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21463417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10731723 + 10731724.

It is an arithmetic number, because the mean of its divisors is an integer number (10731724).

Almost surely, 2^21463447 is an apocalyptic number.

21463447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21463447 is an equidigital number, since it uses as much as digits as its factorization.

21463447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 31.

The square root of 21463447 is about 4632.8659596410. The cubic root of 21463447 is about 277.9072159006.

Adding to 21463447 its reverse (74436412), we get a palindrome (95899859).

The spelling of 21463447 in words is "twenty-one million, four hundred sixty-three thousand, four hundred forty-seven".