21173526047 has 16 divisors (see below), whose sum is σ = 22345735680. Its totient is φ = 20023055712.

The previous prime is 21173526037. The next prime is 21173526053. The reversal of 21173526047 is 74062537112.

It is a cyclic number.

It is not a de Polignac number, because 21173526047 - 2¹² = 21173521951 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21173526047.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21173526037) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1244198 + ... + 1261100.

It is an arithmetic number, because the mean of its divisors is an integer number (1396608480).

Almost surely, 2^21173526047 is an apocalyptic number.

21173526047 is a deficient number, since it is larger than the sum of its proper divisors (1172209633).

21173526047 is a wasteful number, since it uses less digits than its factorization.

21173526047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17542.

The product of its (nonzero) digits is 70560, while the sum is 38.

The spelling of 21173526047 in words is "twenty-one billion, one hundred seventy-three million, five hundred twenty-six thousand, forty-seven".