21536938 has 8 divisors (see below), whose sum is σ = 32538240. Its totient is φ = 10690860.

The previous prime is 21536929. The next prime is 21536939. The reversal of 21536938 is 83963512.

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 = 21536897 and 21536906.

It is not an unprimeable number, because it can be changed into a prime (21536939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38458 + ... + 39013.

It is an arithmetic number, because the mean of its divisors is an integer number (4067280).

Almost surely, 2^21536938 is an apocalyptic number.

21536938 is a deficient number, since it is larger than the sum of its proper divisors (11001302).

21536938 is a wasteful number, since it uses less digits than its factorization.

21536938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77612.

The product of its digits is 38880, while the sum is 37.

The square root of 21536938 is about 4640.7906653931. The cubic root of 21536938 is about 278.2240400213.

The spelling of 21536938 in words is "twenty-one million, five hundred thirty-six thousand, nine hundred thirty-eight".