21643070 has 8 divisors (see below), whose sum is σ = 38957544. Its totient is φ = 8657224.

The previous prime is 21643067. The next prime is 21643073. The reversal of 21643070 is 7034612.

It is an interprime number because it is at equal distance from previous prime (21643067) and next prime (21643073).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21643073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1082144 + ... + 1082163.

It is an arithmetic number, because the mean of its divisors is an integer number (4869693).

Almost surely, 2^21643070 is an apocalyptic number.

21643070 is a deficient number, since it is larger than the sum of its proper divisors (17314474).

21643070 is a wasteful number, since it uses less digits than its factorization.

21643070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2164314.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 21643070 is about 4652.2113021659. The cubic root of 21643070 is about 278.6803119646.

Adding to 21643070 its reverse (7034612), we get a palindrome (28677682).

The spelling of 21643070 in words is "twenty-one million, six hundred forty-three thousand, seventy".