781399145984 has 40 divisors (see below), whose sum is σ = 1611635771328. Its totient is φ = 378096353280.

The previous prime is 781399145983. The next prime is 781399146013. The reversal of 781399145984 is 489541993187.

It is a super-2 number, since 2×781399145984² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781399145981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24599777 + ... + 24631520.

Almost surely, 2^781399145984 is an apocalyptic number.

It is an amenable number.

781399145984 is an abundant number, since it is smaller than the sum of its proper divisors (830236625344).

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

781399145984 is an equidigital number, since it uses as much as digits as its factorization.

781399145984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49231346 (or 49231330 counting only the distinct ones).

The product of its digits is 78382080, while the sum is 68.

The spelling of 781399145984 in words is "seven hundred eighty-one billion, three hundred ninety-nine million, one hundred forty-five thousand, nine hundred eighty-four".