21447593 has 2 divisors, whose sum is σ = 21447594. Its totient is φ = 21447592.

The previous prime is 21447589. The next prime is 21447607. The reversal of 21447593 is 39574412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14645929 + 6801664 = 3827^2 + 2608^2 .

It is a cyclic number.

It is not a de Polignac number, because 21447593 - 2² = 21447589 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21447533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10723796 + 10723797.

It is an arithmetic number, because the mean of its divisors is an integer number (10723797).

Almost surely, 2^21447593 is an apocalyptic number.

It is an amenable number.

21447593 is a deficient number, since it is larger than the sum of its proper divisors (1).

21447593 is an equidigital number, since it uses as much as digits as its factorization.

21447593 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 35.

The square root of 21447593 is about 4631.1546076546. The cubic root of 21447593 is about 277.8387735505.

The spelling of 21447593 in words is "twenty-one million, four hundred forty-seven thousand, five hundred ninety-three".