21736838 has 4 divisors (see below), whose sum is σ = 32605260. Its totient is φ = 10868418.

The previous prime is 21736823. The next prime is 21736843. The reversal of 21736838 is 83863712.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

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, 5434208 + ... + 5434211.

It is an arithmetic number, because the mean of its divisors is an integer number (8151315).

Almost surely, 2^21736838 is an apocalyptic number.

21736838 is a deficient number, since it is larger than the sum of its proper divisors (10868422).

21736838 is a wasteful number, since it uses less digits than its factorization.

21736838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10868421.

The product of its digits is 48384, while the sum is 38.

The square root of 21736838 is about 4662.2781984776. The cubic root of 21736838 is about 279.0821903851.

The spelling of 21736838 in words is "twenty-one million, seven hundred thirty-six thousand, eight hundred thirty-eight".