1919987 has 2 divisors, whose sum is σ = 1919988. Its totient is φ = 1919986.

The previous prime is 1919959. The next prime is 1920001. The reversal of 1919987 is 7899191.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1919987 - 2¹² = 1915891 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1919917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959993 + 959994.

It is an arithmetic number, because the mean of its divisors is an integer number (959994).

2^1919987 is an apocalyptic number.

1919987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919987 is an equidigital number, since it uses as much as digits as its factorization.

1919987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 44.

The square root of 1919987 is about 1385.6359550762. The cubic root of 1919987 is about 124.2890197235.

The spelling of 1919987 in words is "one million, nine hundred nineteen thousand, nine hundred eighty-seven".