1361365891 has 4 divisors (see below), whose sum is σ = 1369235232. Its totient is φ = 1353496552.

The previous prime is 1361365877. The next prime is 1361365919. The reversal of 1361365891 is 1985631631.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1361365891 - 2²¹ = 1359268739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1361365871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3934411 + ... + 3934756.

It is an arithmetic number, because the mean of its divisors is an integer number (342308808).

Almost surely, 2^1361365891 is an apocalyptic number.

1361365891 is a deficient number, since it is larger than the sum of its proper divisors (7869341).

1361365891 is an equidigital number, since it uses as much as digits as its factorization.

1361365891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7869340.

The product of its digits is 116640, while the sum is 43.

The square root of 1361365891 is about 36896.6921417083. The cubic root of 1361365891 is about 1108.3024375104.

The spelling of 1361365891 in words is "one billion, three hundred sixty-one million, three hundred sixty-five thousand, eight hundred ninety-one".