21199663 has 8 divisors (see below), whose sum is σ = 22567680. Its totient is φ = 19845120.

The previous prime is 21199643. The next prime is 21199681. The reversal of 21199663 is 36699112.

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

It is not a de Polignac number, because 21199663 - 2²¹ = 19102511 is a prime.

It is a super-2 number, since 2×21199663² = 898851422627138, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21199603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18 + ... + 6511.

It is an arithmetic number, because the mean of its divisors is an integer number (2820960).

Almost surely, 2^21199663 is an apocalyptic number.

21199663 is a deficient number, since it is larger than the sum of its proper divisors (1368017).

21199663 is a wasteful number, since it uses less digits than its factorization.

21199663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6737.

The product of its digits is 17496, while the sum is 37.

The square root of 21199663 is about 4604.3091772816. The cubic root of 21199663 is about 276.7640342121.

The spelling of 21199663 in words is "twenty-one million, one hundred ninety-nine thousand, six hundred sixty-three".