1278407231920 has 160 divisors (see below), whose sum is σ = 3659203795968. Its totient is φ = 404485069824.

The previous prime is 1278407231911. The next prime is 1278407231923. The reversal of 1278407231920 is 291327048721.

It is not an unprimeable number, because it can be changed into a prime (1278407231923) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29294757 + ... + 29338363.

Almost surely, 2^{1278407231920} is an apocalyptic number.

1278407231920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1278407231920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1829601897984).

1278407231920 is an abundant number, since it is smaller than the sum of its proper divisors (2380796564048).

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

1278407231920 is a wasteful number, since it uses less digits than its factorization.

1278407231920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47667 (or 47661 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 46.

The spelling of 1278407231920 in words is "one trillion, two hundred seventy-eight billion, four hundred seven million, two hundred thirty-one thousand, nine hundred twenty".