1391142449878 has 4 divisors (see below), whose sum is σ = 2086713674820. Its totient is φ = 695571224938.

The previous prime is 1391142449861. The next prime is 1391142449887. The reversal of 1391142449878 is 8789442411931.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347785612468 + ... + 347785612471.

It is an arithmetic number, because the mean of its divisors is an integer number (521678418705).

Almost surely, 2^{1391142449878} is an apocalyptic number.

1391142449878 is a deficient number, since it is larger than the sum of its proper divisors (695571224942).

1391142449878 is an equidigital number, since it uses as much as digits as its factorization.

1391142449878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695571224941.

The product of its digits is 13934592, while the sum is 61.

The spelling of 1391142449878 in words is "one trillion, three hundred ninety-one billion, one hundred forty-two million, four hundred forty-nine thousand, eight hundred seventy-eight".