781018019990 has 128 divisors (see below), whose sum is σ = 1615644092160. Its totient is φ = 269282377728.

The previous prime is 781018019941. The next prime is 781018019993. The reversal of 781018019990 is 99910810187.

781018019990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781018019993) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 322333919 + ... + 322336341.

It is an arithmetic number, because the mean of its divisors is an integer number (12622219470).

Almost surely, 2^781018019990 is an apocalyptic number.

781018019990 is an abundant number, since it is smaller than the sum of its proper divisors (834626072170).

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

781018019990 is a wasteful number, since it uses less digits than its factorization.

781018019990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3546.

The product of its (nonzero) digits is 326592, while the sum is 53.

The spelling of 781018019990 in words is "seven hundred eighty-one billion, eighteen million, nineteen thousand, nine hundred ninety".