21464647 has 2 divisors, whose sum is σ = 21464648. Its totient is φ = 21464646.

The previous prime is 21464633. The next prime is 21464657. The reversal of 21464647 is 74646412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21464647 - 2¹¹ = 21462599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21464627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10732323 + 10732324.

It is an arithmetic number, because the mean of its divisors is an integer number (10732324).

Almost surely, 2^21464647 is an apocalyptic number.

21464647 is a deficient number, since it is larger than the sum of its proper divisors (1).

21464647 is an equidigital number, since it uses as much as digits as its factorization.

21464647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 34.

The square root of 21464647 is about 4632.9954672976. The cubic root of 21464647 is about 277.9123949762.

The spelling of 21464647 in words is "twenty-one million, four hundred sixty-four thousand, six hundred forty-seven".