21400206 has 8 divisors (see below), whose sum is σ = 42800424. Its totient is φ = 7133400.

The previous prime is 21400201. The next prime is 21400217. The reversal of 21400206 is 60200412.

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

21400206 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400201) 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, 1783345 + ... + 1783356.

It is an arithmetic number, because the mean of its divisors is an integer number (5350053).

Almost surely, 2^21400206 is an apocalyptic number.

21400206 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21400206 is a wasteful number, since it uses less digits than its factorization.

21400206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3566706.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21400206 is about 4626.0356678262. The cubic root of 21400206 is about 277.6340006994.

Adding to 21400206 its reverse (60200412), we get a palindrome (81600618).

The spelling of 21400206 in words is "twenty-one million, four hundred thousand, two hundred six".