781677321012 has 432 divisors, whose sum is σ = 2415553201152. Its totient is φ = 212261575680.

The previous prime is 781677320969. The next prime is 781677321013. The reversal of 781677321012 is 210123776187.

It is a super-2 number, since 2×781677321012² (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 (781677321013) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 771645418 + ... + 771646430.

It is an arithmetic number, because the mean of its divisors is an integer number (5591558336).

Almost surely, 2^781677321012 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781677321012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1207776600576).

781677321012 is an abundant number, since it is smaller than the sum of its proper divisors (1633875880140).

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

781677321012 is a wasteful number, since it uses less digits than its factorization.

781677321012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1308 (or 1296 counting only the distinct ones).

The product of its (nonzero) digits is 197568, while the sum is 45.

The spelling of 781677321012 in words is "seven hundred eighty-one billion, six hundred seventy-seven million, three hundred twenty-one thousand, twelve".