21701047 has 2 divisors, whose sum is σ = 21701048. Its totient is φ = 21701046.

The previous prime is 21701041. The next prime is 21701051. The reversal of 21701047 is 74010712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21701047 - 2³ = 21701039 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21701041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10850523 + 10850524.

It is an arithmetic number, because the mean of its divisors is an integer number (10850524).

Almost surely, 2^21701047 is an apocalyptic number.

21701047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21701047 is an equidigital number, since it uses as much as digits as its factorization.

21701047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 21701047 is about 4658.4382576138. The cubic root of 21701047 is about 278.9289310811.

Adding to 21701047 its reverse (74010712), we get a palindrome (95711759).

The spelling of 21701047 in words is "twenty-one million, seven hundred one thousand, forty-seven".