21761347 has 2 divisors, whose sum is σ = 21761348. Its totient is φ = 21761346.

The previous prime is 21761303. The next prime is 21761351. The reversal of 21761347 is 74316712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21761347 - 2⁷ = 21761219 is a prime.

It is not a weakly prime, because it can be changed into another prime (21761387) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10880673 + 10880674.

It is an arithmetic number, because the mean of its divisors is an integer number (10880674).

Almost surely, 2^21761347 is an apocalyptic number.

21761347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21761347 is an equidigital number, since it uses as much as digits as its factorization.

21761347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 31.

The square root of 21761347 is about 4664.9058940133. The cubic root of 21761347 is about 279.1870424374.

The spelling of 21761347 in words is "twenty-one million, seven hundred sixty-one thousand, three hundred forty-seven".