21817172134 has 4 divisors (see below), whose sum is σ = 32725758204. Its totient is φ = 10908586066.

The previous prime is 21817172131. The next prime is 21817172141. The reversal of 21817172134 is 43127171812.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21817172134² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21817172093 and 21817172102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21817172131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5454293032 + ... + 5454293035.

It is an arithmetic number, because the mean of its divisors is an integer number (8181439551).

Almost surely, 2^21817172134 is an apocalyptic number.

21817172134 is a deficient number, since it is larger than the sum of its proper divisors (10908586070).

21817172134 is a wasteful number, since it uses less digits than its factorization.

21817172134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10908586069.

The product of its digits is 18816, while the sum is 37.

The spelling of 21817172134 in words is "twenty-one billion, eight hundred seventeen million, one hundred seventy-two thousand, one hundred thirty-four".