21774045052145 has 4 divisors (see below), whose sum is σ = 26128854062580. Its totient is φ = 17419236041712.

The previous prime is 21774045052087. The next prime is 21774045052171. The reversal of 21774045052145 is 54125054047712.

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 5260972529761 + 16513072522384 = 2293681^2 + 4063628^2 .

It is a cyclic number.

It is not a de Polignac number, because 21774045052145 - 2¹⁶ = 21774044986609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21774045052145.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2177404505210 + ... + 2177404505219.

It is an arithmetic number, because the mean of its divisors is an integer number (6532213515645).

Almost surely, 2^{21774045052145} is an apocalyptic number.

It is an amenable number.

21774045052145 is a deficient number, since it is larger than the sum of its proper divisors (4354809010435).

21774045052145 is an equidigital number, since it uses as much as digits as its factorization.

21774045052145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4354809010434.

The product of its (nonzero) digits is 1568000, while the sum is 47.

Adding to 21774045052145 its reverse (54125054047712), we get a palindrome (75899099099857).

The spelling of 21774045052145 in words is "twenty-one trillion, seven hundred seventy-four billion, forty-five million, fifty-two thousand, one hundred forty-five".