27891400875361 has 9 divisors (see below), whose sum is σ = 27916345287571. Its totient is φ = 27866478746272.

The previous prime is 27891400875269. The next prime is 27891400875379. The reversal of 27891400875361 is 16357800419872.

The square root of 27891400875361 is 5281231.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3159239630625 + 24732161244736 = 1777425^2 + 4973144^2 .

It is a de Polignac number, because none of the positive numbers 2^k-27891400875361 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27891400875361.

It is not an unprimeable number, because it can be changed into a prime (27891400845361) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 9627682665 + ... + 9627685561.

It is a 1-persistent number, because it is pandigital, but 2⋅27891400875361 = 55782801750722 is not.

Almost surely, 2^{27891400875361} is an apocalyptic number.

27891400875361 is the 5281231-st square number.

27891400875361 is the 2640616-th centered octagonal number.

It is an amenable number.

27891400875361 is a deficient number, since it is larger than the sum of its proper divisors (24944412210).

27891400875361 is an frugal number, since it uses more digits than its factorization.

27891400875361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9440 (or 4720 counting only the distinct ones).

The product of its (nonzero) digits is 20321280, while the sum is 61.

The spelling of 27891400875361 in words is "twenty-seven trillion, eight hundred ninety-one billion, four hundred million, eight hundred seventy-five thousand, three hundred sixty-one".