21375171717641 has 32 divisors (see below), whose sum is σ = 25468098969600. Its totient is φ = 17553879864000.

The previous prime is 21375171717607. The next prime is 21375171717733. The reversal of 21375171717641 is 14671717157312.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21375171717641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21375171713641) 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 31 ways as a sum of consecutive naturals, for example, 636167960 + ... + 636201558.

It is an arithmetic number, because the mean of its divisors is an integer number (795878092800).

Almost surely, 2^{21375171717641} is an apocalyptic number.

It is an amenable number.

21375171717641 is a deficient number, since it is larger than the sum of its proper divisors (4092927251959).

21375171717641 is a wasteful number, since it uses less digits than its factorization.

21375171717641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62765.

The product of its digits is 1728720, while the sum is 53.

The spelling of 21375171717641 in words is "twenty-one trillion, three hundred seventy-five billion, one hundred seventy-one million, seven hundred seventeen thousand, six hundred forty-one".