2151717566545 has 4 divisors (see below), whose sum is σ = 2582061079860. Its totient is φ = 1721374053232.

The previous prime is 2151717566507. The next prime is 2151717566567. The reversal of 2151717566545 is 5456657171512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 784398949569 + 1367318616976 = 885663^2 + 1169324^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151717566545 - 2⁷ = 2151717566417 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215171756650 + ... + 215171756659.

It is an arithmetic number, because the mean of its divisors is an integer number (645515269965).

Almost surely, 2^{2151717566545} is an apocalyptic number.

It is an amenable number.

2151717566545 is a deficient number, since it is larger than the sum of its proper divisors (430343513315).

2151717566545 is an equidigital number, since it uses as much as digits as its factorization.

2151717566545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430343513314.

The product of its digits is 8820000, while the sum is 55.

The spelling of 2151717566545 in words is "two trillion, one hundred fifty-one billion, seven hundred seventeen million, five hundred sixty-six thousand, five hundred forty-five".