21375172117613 has 16 divisors (see below), whose sum is σ = 21923298086976. Its totient is φ = 20829378890880.

The previous prime is 21375172117577. The next prime is 21375172117627. The reversal of 21375172117613 is 31671127157312.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21375172117613 - 2⁸ = 21375172117357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21375172117643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142453718 + ... + 142603688.

It is an arithmetic number, because the mean of its divisors is an integer number (1370206130436).

Almost surely, 2^{21375172117613} is an apocalyptic number.

It is an amenable number.

21375172117613 is a deficient number, since it is larger than the sum of its proper divisors (548125969363).

21375172117613 is a wasteful number, since it uses less digits than its factorization.

21375172117613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157724.

The product of its digits is 370440, while the sum is 47.

The spelling of 21375172117613 in words is "twenty-one trillion, three hundred seventy-five billion, one hundred seventy-two million, one hundred seventeen thousand, six hundred thirteen".