21098819 has 8 divisors (see below), whose sum is σ = 25531488. Its totient is φ = 17020800.

The previous prime is 21098807. The next prime is 21098837. The reversal of 21098819 is 91889012.

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 21098819 - 2⁸ = 21098563 is a prime.

It is a super-2 number, since 2×21098819² = 890320326389522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21098839) 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, 88532 + ... + 88769.

It is an arithmetic number, because the mean of its divisors is an integer number (3191436).

Almost surely, 2^21098819 is an apocalyptic number.

21098819 is a deficient number, since it is larger than the sum of its proper divisors (4432669).

21098819 is a wasteful number, since it uses less digits than its factorization.

21098819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177325.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 21098819 is about 4593.3450773919. The cubic root of 21098819 is about 276.3244931951.

The spelling of 21098819 in words is "twenty-one million, ninety-eight thousand, eight hundred nineteen".