21055199 has 8 divisors (see below), whose sum is σ = 23112192. Its totient is φ = 19022040.

The previous prime is 21055147. The next prime is 21055207. The reversal of 21055199 is 99155012.

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

It is a cyclic number.

It is not a de Polignac number, because 21055199 - 2¹² = 21051103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21055399) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 4079 + ... + 7664.

It is an arithmetic number, because the mean of its divisors is an integer number (2889024).

Almost surely, 2^21055199 is an apocalyptic number.

21055199 is a deficient number, since it is larger than the sum of its proper divisors (2056993).

21055199 is a wasteful number, since it uses less digits than its factorization.

21055199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11917.

The product of its (nonzero) digits is 4050, while the sum is 32.

The square root of 21055199 is about 4588.5944471047. The cubic root of 21055199 is about 276.1339360788.

The spelling of 21055199 in words is "twenty-one million, fifty-five thousand, one hundred ninety-nine".