21006856203 has 8 divisors (see below), whose sum is σ = 28194633216. Its totient is φ = 13911825000.

The previous prime is 21006856163. The next prime is 21006856219. The reversal of 21006856203 is 30265860012.

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

It is not a de Polignac number, because 21006856203 - 2⁶ = 21006856139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21006856243) 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, 23185923 + ... + 23186828.

It is an arithmetic number, because the mean of its divisors is an integer number (3524329152).

Almost surely, 2^21006856203 is an apocalyptic number.

21006856203 is a deficient number, since it is larger than the sum of its proper divisors (7187777013).

21006856203 is a wasteful number, since it uses less digits than its factorization.

21006856203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46372905.

The product of its (nonzero) digits is 17280, while the sum is 33.

The spelling of 21006856203 in words is "twenty-one billion, six million, eight hundred fifty-six thousand, two hundred three".