21172225127 has 4 divisors (see below), whose sum is σ = 21263093280. Its totient is φ = 21081356976.

The previous prime is 21172225111. The next prime is 21172225133. The reversal of 21172225127 is 72152227112.

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

It is a cyclic number.

It is not a de Polignac number, because 21172225127 - 2⁴ = 21172225111 is a prime.

It is a super-3 number, since 3×21172225127³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21172225093 and 21172225102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21172225177) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45433727 + ... + 45434192.

It is an arithmetic number, because the mean of its divisors is an integer number (5315773320).

Almost surely, 2^21172225127 is an apocalyptic number.

21172225127 is a deficient number, since it is larger than the sum of its proper divisors (90868153).

21172225127 is an equidigital number, since it uses as much as digits as its factorization.

21172225127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90868152.

The product of its digits is 7840, while the sum is 32.

The spelling of 21172225127 in words is "twenty-one billion, one hundred seventy-two million, two hundred twenty-five thousand, one hundred twenty-seven".