1256780366780 has 24 divisors (see below), whose sum is σ = 2710569549408. Its totient is φ = 489125331648.

The previous prime is 1256780366771. The next prime is 1256780366851. The reversal of 1256780366780 is 876630876521.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 849175184 + ... + 849176663.

It is an arithmetic number, because the mean of its divisors is an integer number (112940397892).

Almost surely, 2^{1256780366780} is an apocalyptic number.

1256780366780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1256780366780 is an abundant number, since it is smaller than the sum of its proper divisors (1453789182628).

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

1256780366780 is a wasteful number, since it uses less digits than its factorization.

1256780366780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1698351893 (or 1698351891 counting only the distinct ones).

The product of its (nonzero) digits is 20321280, while the sum is 59.

The spelling of 1256780366780 in words is "one trillion, two hundred fifty-six billion, seven hundred eighty million, three hundred sixty-six thousand, seven hundred eighty".