21134172673 has 4 divisors (see below), whose sum is σ = 21214531008. Its totient is φ = 21053814340.

The previous prime is 21134172649. The next prime is 21134172691. The reversal of 21134172673 is 37627143112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21134172673 - 2²⁵ = 21100618241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21134172623) 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, 40178773 + ... + 40179298.

It is an arithmetic number, because the mean of its divisors is an integer number (5303632752).

Almost surely, 2^21134172673 is an apocalyptic number.

It is an amenable number.

21134172673 is a deficient number, since it is larger than the sum of its proper divisors (80358335).

21134172673 is an equidigital number, since it uses as much as digits as its factorization.

21134172673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80358334.

The product of its digits is 42336, while the sum is 37.

The spelling of 21134172673 in words is "twenty-one billion, one hundred thirty-four million, one hundred seventy-two thousand, six hundred seventy-three".