21606478223 has 8 divisors (see below), whose sum is σ = 23600663040. Its totient is φ = 19617286680.

The previous prime is 21606478213. The next prime is 21606478247. The reversal of 21606478223 is 32287460612.

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 21606478223 - 2⁸ = 21606477967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606478213) 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, 1239263 + ... + 1256576.

It is an arithmetic number, because the mean of its divisors is an integer number (2950082880).

Almost surely, 2^21606478223 is an apocalyptic number.

21606478223 is a deficient number, since it is larger than the sum of its proper divisors (1994184817).

21606478223 is a wasteful number, since it uses less digits than its factorization.

21606478223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2496637.

The product of its (nonzero) digits is 193536, while the sum is 41.

The spelling of 21606478223 in words is "twenty-one billion, six hundred six million, four hundred seventy-eight thousand, two hundred twenty-three".