1121558396778 has 24 divisors (see below), whose sum is σ = 2430083194500. Its totient is φ = 373846644864.

The previous prime is 1121558396741. The next prime is 1121558396801. The reversal of 1121558396778 is 8776938551211.

It is a happy number.

1121558396778 is a `hidden beast` number, since 1 + 1 + 2 + 1 + 558 + 3 + 9 + 6 + 7 + 78 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1121233207689 + 325189089 = 1058883^2 + 18033^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 686868 + ... + 1647696.

Almost surely, 2^{1121558396778} is an apocalyptic number.

1121558396778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1121558396778 is an abundant number, since it is smaller than the sum of its proper divisors (1308524797722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1121558396778 is a wasteful number, since it uses less digits than its factorization.

1121558396778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025686 (or 1025683 counting only the distinct ones).

The product of its digits is 25401600, while the sum is 63.

The spelling of 1121558396778 in words is "one trillion, one hundred twenty-one billion, five hundred fifty-eight million, three hundred ninety-six thousand, seven hundred seventy-eight".