21401206 has 4 divisors (see below), whose sum is σ = 32101812. Its totient is φ = 10700602.

The previous prime is 21401203. The next prime is 21401251. The reversal of 21401206 is 60210412.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21401206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401203) 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 as a sum of consecutive naturals, namely, 5350300 + ... + 5350303.

It is an arithmetic number, because the mean of its divisors is an integer number (8025453).

Almost surely, 2^21401206 is an apocalyptic number.

21401206 is a deficient number, since it is larger than the sum of its proper divisors (10700606).

21401206 is a wasteful number, since it uses less digits than its factorization.

21401206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10700605.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21401206 is about 4626.1437504686. The cubic root of 21401206 is about 277.6383251075.

Adding to 21401206 its reverse (60210412), we get a palindrome (81611618).

The spelling of 21401206 in words is "twenty-one million, four hundred one thousand, two hundred six".