21787672210123 has 4 divisors (see below), whose sum is σ = 22376528215840. Its totient is φ = 21198816204408.

The previous prime is 21787672210039. The next prime is 21787672210159. The reversal of 21787672210123 is 32101227678712.

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 21787672210123 - 2⁴¹ = 19588648954571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21787672219123) 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, 294428002803 + ... + 294428002876.

It is an arithmetic number, because the mean of its divisors is an integer number (5594132053960).

Almost surely, 2^{21787672210123} is an apocalyptic number.

21787672210123 is a deficient number, since it is larger than the sum of its proper divisors (588856005717).

21787672210123 is an equidigital number, since it uses as much as digits as its factorization.

21787672210123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588856005716.

The product of its (nonzero) digits is 790272, while the sum is 49.

Adding to 21787672210123 its reverse (32101227678712), we get a palindrome (53888899888835).

The spelling of 21787672210123 in words is "twenty-one trillion, seven hundred eighty-seven billion, six hundred seventy-two million, two hundred ten thousand, one hundred twenty-three".