21138801 has 8 divisors (see below), whose sum is σ = 28213344. Its totient is φ = 14078400.

The previous prime is 21138791. The next prime is 21138823. The reversal of 21138801 is 10883112.

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

It is not a de Polignac number, because 21138801 - 2⁶ = 21138737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21138851) 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 7 ways as a sum of consecutive naturals, for example, 670 + ... + 6536.

It is an arithmetic number, because the mean of its divisors is an integer number (3526668).

Almost surely, 2^21138801 is an apocalyptic number.

It is an amenable number.

21138801 is a deficient number, since it is larger than the sum of its proper divisors (7074543).

21138801 is a wasteful number, since it uses less digits than its factorization.

21138801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7071.

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 21138801 is about 4597.6951834588. The cubic root of 21138801 is about 276.4989268859.

The spelling of 21138801 in words is "twenty-one million, one hundred thirty-eight thousand, eight hundred one".