21042800172 has 36 divisors (see below), whose sum is σ = 53220183016. Its totient is φ = 7010487360.

The previous prime is 21042800167. The next prime is 21042800227. The reversal of 21042800172 is 27100824012.

21042800172 is a `hidden beast` number, since 210 + 4 + 280 + 0 + 172 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 89329 + ... + 223752.

Almost surely, 2^21042800172 is an apocalyptic number.

It is an amenable number.

21042800172 is an abundant number, since it is smaller than the sum of its proper divisors (32177382844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21042800172 is a wasteful number, since it uses less digits than its factorization.

21042800172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314958 (or 314953 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

It can be divided in two parts, 2104 and 2800172, that added together give a square (2802276 = 1674²).

The spelling of 21042800172 in words is "twenty-one billion, forty-two million, eight hundred thousand, one hundred seventy-two".