21700147 has 16 divisors (see below), whose sum is σ = 26288640. Its totient is φ = 17497728.

The previous prime is 21700127. The next prime is 21700169. The reversal of 21700147 is 74100712.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21700147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21700117) 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 in 15 ways as a sum of consecutive naturals, for example, 21723 + ... + 22699.

It is an arithmetic number, because the mean of its divisors is an integer number (1643040).

Almost surely, 2^21700147 is an apocalyptic number.

21700147 is a deficient number, since it is larger than the sum of its proper divisors (4588493).

21700147 is a wasteful number, since it uses less digits than its factorization.

21700147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1170.

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

The square root of 21700147 is about 4658.3416577147. The cubic root of 21700147 is about 278.9250750535.

Adding to 21700147 its reverse (74100712), we get a palindrome (95800859).

The spelling of 21700147 in words is "twenty-one million, seven hundred thousand, one hundred forty-seven".