1019109281821 has 4 divisors (see below), whose sum is σ = 1079056886652. Its totient is φ = 959161676992.

The previous prime is 1019109281783. The next prime is 1019109281849. The reversal of 1019109281821 is 1281829019101.

1019109281821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 345373659225 + 673735622596 = 587685^2 + 820814^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1019109281821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1019109281221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29973802390 + ... + 29973802423.

It is an arithmetic number, because the mean of its divisors is an integer number (269764221663).

Almost surely, 2^{1019109281821} is an apocalyptic number.

It is an amenable number.

1019109281821 is a deficient number, since it is larger than the sum of its proper divisors (59947604831).

1019109281821 is an equidigital number, since it uses as much as digits as its factorization.

1019109281821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59947604830.

The product of its (nonzero) digits is 20736, while the sum is 43.

The spelling of 1019109281821 in words is "one trillion, nineteen billion, one hundred nine million, two hundred eighty-one thousand, eight hundred twenty-one".