1428781221780 has 384 divisors, whose sum is σ = 4583658627072. Its totient is φ = 329521920000.

The previous prime is 1428781221773. The next prime is 1428781221793. The reversal of 1428781221780 is 871221878241.

It is a super-2 number, since 2×1428781221780² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 151493665 + ... + 151503095.

It is an arithmetic number, because the mean of its divisors is an integer number (11936611008).

Almost surely, 2^{1428781221780} is an apocalyptic number.

1428781221780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1428781221780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2291829313536).

1428781221780 is an abundant number, since it is smaller than the sum of its proper divisors (3154877405292).

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

1428781221780 is a wasteful number, since it uses less digits than its factorization.

1428781221780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9639 (or 9637 counting only the distinct ones).

The product of its (nonzero) digits is 802816, while the sum is 51.

It can be divided in two parts, 1428781 and 221780, that added together give a palindrome (1650561).

The spelling of 1428781221780 in words is "one trillion, four hundred twenty-eight billion, seven hundred eighty-one million, two hundred twenty-one thousand, seven hundred eighty".