21173878203 has 8 divisors (see below), whose sum is σ = 28234633728. Its totient is φ = 14114520744.

The previous prime is 21173878181. The next prime is 21173878241. The reversal of 21173878203 is 30287837112.

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

It is not a de Polignac number, because 21173878203 - 2⁶ = 21173878139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21173808203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 313651 + ... + 375132.

It is an arithmetic number, because the mean of its divisors is an integer number (3529329216).

Almost surely, 2^21173878203 is an apocalyptic number.

21173878203 is a deficient number, since it is larger than the sum of its proper divisors (7060755525).

21173878203 is a wasteful number, since it uses less digits than its factorization.

21173878203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699033.

The product of its (nonzero) digits is 112896, while the sum is 42.

It can be divided in two parts, 211738 and 78203, that added together give a triangular number (289941 = T₇₆₁).

The spelling of 21173878203 in words is "twenty-one billion, one hundred seventy-three million, eight hundred seventy-eight thousand, two hundred three".