21623163 has 8 divisors (see below), whose sum is σ = 28862976. Its totient is φ = 14399400.

The previous prime is 21623153. The next prime is 21623171. The reversal of 21623163 is 36132612.

It is a happy number.

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

It is not a de Polignac number, because 21623163 - 2⁵ = 21623131 is a prime.

It is a super-2 number, since 2×21623163² = 935122356249138, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21623153) 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, 403 + ... + 6588.

It is an arithmetic number, because the mean of its divisors is an integer number (3607872).

Almost surely, 2^21623163 is an apocalyptic number.

21623163 is a deficient number, since it is larger than the sum of its proper divisors (7239813).

21623163 is a wasteful number, since it uses less digits than its factorization.

21623163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8025.

The product of its digits is 1296, while the sum is 24.

The square root of 21623163 is about 4650.0712897761. The cubic root of 21623163 is about 278.5948436409.

Adding to 21623163 its reverse (36132612), we get a palindrome (57755775).

The spelling of 21623163 in words is "twenty-one million, six hundred twenty-three thousand, one hundred sixty-three".