21607438 has 8 divisors (see below), whose sum is σ = 32430888. Its totient is φ = 10797144.

The previous prime is 21607409. The next prime is 21607441. The reversal of 21607438 is 83470612.

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

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, 4720 + ... + 8092.

It is an arithmetic number, because the mean of its divisors is an integer number (4053861).

Almost surely, 2^21607438 is an apocalyptic number.

21607438 is a deficient number, since it is larger than the sum of its proper divisors (10823450).

21607438 is a wasteful number, since it uses less digits than its factorization.

21607438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6578.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21607438 is about 4648.3801479655. The cubic root of 21607438 is about 278.5272931424.

The spelling of 21607438 in words is "twenty-one million, six hundred seven thousand, four hundred thirty-eight".