21431606 has 8 divisors (see below), whose sum is σ = 36739920. Its totient is φ = 9184968.

The previous prime is 21431593. The next prime is 21431623. The reversal of 21431606 is 60613412.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 765401 + ... + 765428.

It is an arithmetic number, because the mean of its divisors is an integer number (4592490).

Almost surely, 2^21431606 is an apocalyptic number.

21431606 is a deficient number, since it is larger than the sum of its proper divisors (15308314).

21431606 is a wasteful number, since it uses less digits than its factorization.

21431606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1530838.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21431606 is about 4629.4282584354. The cubic root of 21431606 is about 277.7697228716.

The spelling of 21431606 in words is "twenty-one million, four hundred thirty-one thousand, six hundred six".