1921144919 has 4 divisors (see below), whose sum is σ = 1952639160. Its totient is φ = 1889650680.

The previous prime is 1921144903. The next prime is 1921144921. The reversal of 1921144919 is 9194411291.

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

It is not a de Polignac number, because 1921144919 - 2⁴ = 1921144903 is a prime.

It is a super-2 number, since 2×1921144919² = 7381595599599033122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921144319) 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, 15747029 + ... + 15747150.

It is an arithmetic number, because the mean of its divisors is an integer number (488159790).

Almost surely, 2^1921144919 is an apocalyptic number.

1921144919 is a deficient number, since it is larger than the sum of its proper divisors (31494241).

1921144919 is an equidigital number, since it uses as much as digits as its factorization.

1921144919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31494240.

The product of its digits is 23328, while the sum is 41.

The square root of 1921144919 is about 43830.8671942502. The cubic root of 1921144919 is about 1243.1400039534.

The spelling of 1921144919 in words is "one billion, nine hundred twenty-one million, one hundred forty-four thousand, nine hundred nineteen".