1901993 has 2 divisors, whose sum is σ = 1901994. Its totient is φ = 1901992.

The previous prime is 1901987. The next prime is 1902007. The reversal of 1901993 is 3991091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1658944 + 243049 = 1288^2 + 493^2 .

It is a cyclic number.

It is not a de Polignac number, because 1901993 - 2¹⁸ = 1639849 is a prime.

It is not a weakly prime, because it can be changed into another prime (1901923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950996 + 950997.

It is an arithmetic number, because the mean of its divisors is an integer number (950997).

2^1901993 is an apocalyptic number.

It is an amenable number.

1901993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1901993 is an equidigital number, since it uses as much as digits as its factorization.

1901993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 1901993 is about 1379.1276228109. The cubic root of 1901993 is about 123.8995240531.

The spelling of 1901993 in words is "one million, nine hundred one thousand, nine hundred ninety-three".