21170101 has 2 divisors, whose sum is σ = 21170102. Its totient is φ = 21170100.

The previous prime is 21170099. The next prime is 21170113. The reversal of 21170101 is 10107112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21169201 + 900 = 4601^2 + 30^2 .

It is a cyclic number.

It is not a de Polignac number, because 21170101 - 2¹ = 21170099 is a prime.

Together with 21170099, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21170131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10585050 + 10585051.

It is an arithmetic number, because the mean of its divisors is an integer number (10585051).

Almost surely, 2^21170101 is an apocalyptic number.

It is an amenable number.

21170101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21170101 is an equidigital number, since it uses as much as digits as its factorization.

21170101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14, while the sum is 13.

The square root of 21170101 is about 4601.0978037855. The cubic root of 21170101 is about 276.6353292678.

Adding to 21170101 its reverse (10107112), we get a palindrome (31277213).

The spelling of 21170101 in words is "twenty-one million, one hundred seventy thousand, one hundred one".