1021378881600 has 504 divisors, whose sum is σ = 4525995609408. Its totient is φ = 212234342400.

The previous prime is 1021378881571. The next prime is 1021378881631. The reversal of 1021378881600 is 61888731201.

It is a happy number.

1021378881600 is a `hidden beast` number, since 1 + 0 + 2 + 1 + 37 + 8 + 8 + 8 + 1 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 648222 + ... + 1569378.

Almost surely, 2^{1021378881600} is an apocalyptic number.

1021378881600 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 1021378881600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2262997804704).

1021378881600 is an abundant number, since it is smaller than the sum of its proper divisors (3504616727808).

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

1021378881600 is a wasteful number, since it uses less digits than its factorization.

1021378881600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921203 (or 921185 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The spelling of 1021378881600 in words is "one trillion, twenty-one billion, three hundred seventy-eight million, eight hundred eighty-one thousand, six hundred".