781219797906 has 16 divisors (see below), whose sum is σ = 1562450479200. Its totient is φ = 260404785408.

The previous prime is 781219797901. The next prime is 781219797947. The reversal of 781219797906 is 609797912187.

It is a happy number.

It is a super-2 number, since 2×781219797906² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (781219797901) 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 7 ways as a sum of consecutive naturals, for example, 708850 + ... + 1436978.

It is an arithmetic number, because the mean of its divisors is an integer number (97653154950).

Almost surely, 2^781219797906 is an apocalyptic number.

781219797906 is an abundant number, since it is smaller than the sum of its proper divisors (781230681294).

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

781219797906 is a wasteful number, since it uses less digits than its factorization.

781219797906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 906953.

The product of its (nonzero) digits is 24004512, while the sum is 66.

The spelling of 781219797906 in words is "seven hundred eighty-one billion, two hundred nineteen million, seven hundred ninety-seven thousand, nine hundred six".