1919139312421 has 4 divisors (see below), whose sum is σ = 1922954699232. Its totient is φ = 1915323925612.

The previous prime is 1919139312371. The next prime is 1919139312451. The reversal of 1919139312421 is 1242139319191.

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 1919139312421 - 2²¹ = 1919137215269 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 (1919139312451) 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, 1907692651 + ... + 1907693656.

It is an arithmetic number, because the mean of its divisors is an integer number (480738674808).

Almost surely, 2^{1919139312421} is an apocalyptic number.

It is an amenable number.

1919139312421 is a deficient number, since it is larger than the sum of its proper divisors (3815386811).

1919139312421 is an equidigital number, since it uses as much as digits as its factorization.

1919139312421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3815386810.

The product of its digits is 104976, while the sum is 46.

The spelling of 1919139312421 in words is "one trillion, nine hundred nineteen billion, one hundred thirty-nine million, three hundred twelve thousand, four hundred twenty-one".