1921819 has 2 divisors, whose sum is σ = 1921820. Its totient is φ = 1921818.

The previous prime is 1921813. The next prime is 1921823. The reversal of 1921819 is 9181291.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1921819 - 2⁷ = 1921691 is a prime.

It is a super-2 number, since 2×1921819² = 7386776537522, which contains 22 as substring.

1921819 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1921813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960909 + 960910.

It is an arithmetic number, because the mean of its divisors is an integer number (960910).

2^1921819 is an apocalyptic number.

1921819 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921819 is an equidigital number, since it uses as much as digits as its factorization.

1921819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 31.

The square root of 1921819 is about 1386.2968657542. The cubic root of 1921819 is about 124.3285382378.

The spelling of 1921819 in words is "one million, nine hundred twenty-one thousand, eight hundred nineteen".