1151173981978 has 4 divisors (see below), whose sum is σ = 1726760972970. Its totient is φ = 575586990988.

The previous prime is 1151173981931. The next prime is 1151173982033. The reversal of 1151173981978 is 8791893711511.

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

It can be written as a sum of positive squares in only one way, i.e., 1148997479569 + 2176502409 = 1071913^2 + 46653^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 287793495493 + ... + 287793495496.

Almost surely, 2^{1151173981978} is an apocalyptic number.

1151173981978 is a deficient number, since it is larger than the sum of its proper divisors (575586990992).

1151173981978 is an equidigital number, since it uses as much as digits as its factorization.

1151173981978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575586990991.

The product of its digits is 3810240, while the sum is 61.

The spelling of 1151173981978 in words is "one trillion, one hundred fifty-one billion, one hundred seventy-three million, nine hundred eighty-one thousand, nine hundred seventy-eight".