21800138 has 8 divisors (see below), whose sum is σ = 32761632. Its totient is φ = 10879596.

The previous prime is 21800131. The next prime is 21800189. The reversal of 21800138 is 83100812.

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

It is not an unprimeable number, because it can be changed into a prime (21800131) by changing a digit.

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, 8870 + ... + 11057.

It is an arithmetic number, because the mean of its divisors is an integer number (4095204).

Almost surely, 2^21800138 is an apocalyptic number.

21800138 is a deficient number, since it is larger than the sum of its proper divisors (10961494).

21800138 is a wasteful number, since it uses less digits than its factorization.

21800138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20476.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 21800138 is about 4669.0617901244. The cubic root of 21800138 is about 279.3528335824.

The spelling of 21800138 in words is "twenty-one million, eight hundred thousand, one hundred thirty-eight".