21414947 has 2 divisors, whose sum is σ = 21414948. Its totient is φ = 21414946.

The previous prime is 21414941. The next prime is 21414959. The reversal of 21414947 is 74941412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21414947 - 2²⁰ = 20366371 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (21414941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10707473 + 10707474.

It is an arithmetic number, because the mean of its divisors is an integer number (10707474).

Almost surely, 2^21414947 is an apocalyptic number.

21414947 is a deficient number, since it is larger than the sum of its proper divisors (1).

21414947 is an equidigital number, since it uses as much as digits as its factorization.

21414947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 32.

The square root of 21414947 is about 4627.6286583951. The cubic root of 21414947 is about 277.6977331617.

The spelling of 21414947 in words is "twenty-one million, four hundred fourteen thousand, nine hundred forty-seven".