1921209121193 has 4 divisors (see below), whose sum is σ = 1921928408448. Its totient is φ = 1920489833940.

The previous prime is 1921209121147. The next prime is 1921209121207. The reversal of 1921209121193 is 3911219021291.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1921209121193 - 2⁶ = 1921209121129 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1921209121193.

It is not an unprimeable number, because it can be changed into a prime (1921209121093) 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, 359639621 + ... + 359644962.

It is an arithmetic number, because the mean of its divisors is an integer number (480482102112).

Almost surely, 2^{1921209121193} is an apocalyptic number.

It is an amenable number.

1921209121193 is a deficient number, since it is larger than the sum of its proper divisors (719287255).

1921209121193 is an equidigital number, since it uses as much as digits as its factorization.

1921209121193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719287254.

The product of its (nonzero) digits is 17496, while the sum is 41.

It can be divided in two parts, 1921209 and 121193, that added together give a palindrome (2042402).

The spelling of 1921209121193 in words is "one trillion, nine hundred twenty-one billion, two hundred nine million, one hundred twenty-one thousand, one hundred ninety-three".