21741847 has 2 divisors, whose sum is σ = 21741848. Its totient is φ = 21741846.

The previous prime is 21741823. The next prime is 21741869. The reversal of 21741847 is 74814712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21741847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21741817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10870923 + 10870924.

It is an arithmetic number, because the mean of its divisors is an integer number (10870924).

Almost surely, 2^21741847 is an apocalyptic number.

21741847 is a deficient number, since it is larger than the sum of its proper divisors (1).

21741847 is an equidigital number, since it uses as much as digits as its factorization.

21741847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12544, while the sum is 34.

The square root of 21741847 is about 4662.8153512658. The cubic root of 21741847 is about 279.1036258138.

The spelling of 21741847 in words is "twenty-one million, seven hundred forty-one thousand, eight hundred forty-seven".