1911919393821 has 4 divisors (see below), whose sum is σ = 2549225858432. Its totient is φ = 1274612929212.

The previous prime is 1911919393807. The next prime is 1911919393961. The reversal of 1911919393821 is 1283939191191.

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 not a de Polignac number, because 1911919393821 - 2⁶ = 1911919393757 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 (1911919393801) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 318653232301 + ... + 318653232306.

It is an arithmetic number, because the mean of its divisors is an integer number (637306464608).

Almost surely, 2^{1911919393821} is an apocalyptic number.

It is an amenable number.

1911919393821 is a deficient number, since it is larger than the sum of its proper divisors (637306464611).

1911919393821 is an equidigital number, since it uses as much as digits as its factorization.

1911919393821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637306464610.

The product of its digits is 944784, while the sum is 57.

The spelling of 1911919393821 in words is "one trillion, nine hundred eleven billion, nine hundred nineteen million, three hundred ninety-three thousand, eight hundred twenty-one".