21106207 has 8 divisors (see below), whose sum is σ = 22264560. Its totient is φ = 19952640.

The previous prime is 21106201. The next prime is 21106213. The reversal of 21106207 is 70260112.

It is an interprime number because it is at equal distance from previous prime (21106201) and next prime (21106213).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21106207 - 2³ = 21106199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21106201) 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 7 ways as a sum of consecutive naturals, for example, 11313 + ... + 13045.

It is an arithmetic number, because the mean of its divisors is an integer number (2783070).

Almost surely, 2^21106207 is an apocalyptic number.

21106207 is a deficient number, since it is larger than the sum of its proper divisors (1158353).

21106207 is a wasteful number, since it uses less digits than its factorization.

21106207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2393.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 21106207 is about 4594.1492139459. The cubic root of 21106207 is about 276.3567421900.

Adding to 21106207 its reverse (70260112), we get a palindrome (91366319).

The spelling of 21106207 in words is "twenty-one million, one hundred six thousand, two hundred seven".