21799646 has 8 divisors (see below), whose sum is σ = 35672184. Its totient is φ = 9908920.

The previous prime is 21799643. The next prime is 21799649. The reversal of 21799646 is 64699712.

It is an interprime number because it is at equal distance from previous prime (21799643) and next prime (21799649).

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

It is a junction number, because it is equal to n+sod(n) for n = 21799597 and 21799606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21799643) 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 3 ways as a sum of consecutive naturals, for example, 495425 + ... + 495468.

It is an arithmetic number, because the mean of its divisors is an integer number (4459023).

Almost surely, 2^21799646 is an apocalyptic number.

21799646 is a deficient number, since it is larger than the sum of its proper divisors (13872538).

21799646 is a wasteful number, since it uses less digits than its factorization.

21799646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990906.

The product of its digits is 163296, while the sum is 44.

The square root of 21799646 is about 4669.0091025827. The cubic root of 21799646 is about 279.3507320264.

The spelling of 21799646 in words is "twenty-one million, seven hundred ninety-nine thousand, six hundred forty-six".