2161654215445 has 4 divisors (see below), whose sum is σ = 2593985058540. Its totient is φ = 1729323372352.

The previous prime is 2161654215421. The next prime is 2161654215449. The reversal of 2161654215445 is 5445124561612.

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 321469722289 + 1840184493156 = 566983^2 + 1356534^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161654215445 - 2²⁷ = 2161519997717 is a prime.

It is a super-2 number, since 2×2161654215445² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2161654215395 and 2161654215404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161654215449) 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, 216165421540 + ... + 216165421549.

It is an arithmetic number, because the mean of its divisors is an integer number (648496264635).

Almost surely, 2^{2161654215445} is an apocalyptic number.

It is an amenable number.

2161654215445 is a deficient number, since it is larger than the sum of its proper divisors (432330843095).

2161654215445 is an equidigital number, since it uses as much as digits as its factorization.

2161654215445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432330843094.

The product of its digits is 1152000, while the sum is 46.

The spelling of 2161654215445 in words is "two trillion, one hundred sixty-one billion, six hundred fifty-four million, two hundred fifteen thousand, four hundred forty-five".