21010147 has 4 divisors (see below), whose sum is σ = 22246056. Its totient is φ = 19774240.

The previous prime is 21010127. The next prime is 21010153. The reversal of 21010147 is 74101012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010147 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21010147.

It is not an unprimeable number, because it can be changed into a prime (21010127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 617929 + ... + 617962.

It is an arithmetic number, because the mean of its divisors is an integer number (5561514).

Almost surely, 2^21010147 is an apocalyptic number.

21010147 is a deficient number, since it is larger than the sum of its proper divisors (1235909).

21010147 is a wasteful number, since it uses less digits than its factorization.

21010147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235908.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21010147 is about 4583.6826897158. The cubic root of 21010147 is about 275.9368466792.

Adding to 21010147 its reverse (74101012), we get a palindrome (95111159).

The spelling of 21010147 in words is "twenty-one million, ten thousand, one hundred forty-seven".