1205805126778 has 16 divisors (see below), whose sum is σ = 2067138676800. Its totient is φ = 516762582336.

The previous prime is 1205805126751. The next prime is 1205805126791. The reversal of 1205805126778 is 8776215085021.

It is a super-2 number, since 2×1205805126778² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223576 + ... + 1568947.

It is an arithmetic number, because the mean of its divisors is an integer number (129196167300).

Almost surely, 2^{1205805126778} is an apocalyptic number.

1205805126778 is a deficient number, since it is larger than the sum of its proper divisors (861333550022).

1205805126778 is a wasteful number, since it uses less digits than its factorization.

1205805126778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1840581.

The product of its (nonzero) digits is 1881600, while the sum is 52.

The spelling of 1205805126778 in words is "one trillion, two hundred five billion, eight hundred five million, one hundred twenty-six thousand, seven hundred seventy-eight".