21131692872673 has 8 divisors (see below), whose sum is σ = 21142165941000. Its totient is φ = 21121222161408.

The previous prime is 21131692872671. The next prime is 21131692872767. The reversal of 21131692872673 is 37627829613112.

It can be written as a sum of positive squares in 4 ways, for example, as 8802240458449 + 12329452414224 = 2966857^2 + 3511332^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21131692872673 - 2¹ = 21131692872671 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131692872671) 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 7 ways as a sum of consecutive naturals, for example, 17482765 + ... + 18652357.

It is an arithmetic number, because the mean of its divisors is an integer number (2642770742625).

Almost surely, 2^{21131692872673} is an apocalyptic number.

It is an amenable number.

21131692872673 is a deficient number, since it is larger than the sum of its proper divisors (10473068327).

21131692872673 is a wasteful number, since it uses less digits than its factorization.

21131692872673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1178531.

The product of its digits is 9144576, while the sum is 58.

The spelling of 21131692872673 in words is "twenty-one trillion, one hundred thirty-one billion, six hundred ninety-two million, eight hundred seventy-two thousand, six hundred seventy-three".