21607838 has 8 divisors (see below), whose sum is σ = 37042032. Its totient is φ = 9260496.

The previous prime is 21607829. The next prime is 21607841. The reversal of 21607838 is 83870612.

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

It is a junction number, because it is equal to n+sod(n) for n = 21607798 and 21607807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 771695 + ... + 771722.

It is an arithmetic number, because the mean of its divisors is an integer number (4630254).

Almost surely, 2^21607838 is an apocalyptic number.

21607838 is a deficient number, since it is larger than the sum of its proper divisors (15434194).

21607838 is a wasteful number, since it uses less digits than its factorization.

21607838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543426.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 21607838 is about 4648.4231735073. The cubic root of 21607838 is about 278.5290118442.

The spelling of 21607838 in words is "twenty-one million, six hundred seven thousand, eight hundred thirty-eight".