1993691 has 4 divisors (see below), whose sum is σ = 2278512. Its totient is φ = 1708872.

The previous prime is 1993687. The next prime is 1993697. The reversal of 1993691 is 1963991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1963991 = 1319 ⋅1489.

It is a cyclic number.

It is not a de Polignac number, because 1993691 - 2² = 1993687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1993697) 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, 142400 + ... + 142413.

It is an arithmetic number, because the mean of its divisors is an integer number (569628).

2^1993691 is an apocalyptic number.

1993691 is a deficient number, since it is larger than the sum of its proper divisors (284821).

1993691 is an equidigital number, since it uses as much as digits as its factorization.

1993691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284820.

The product of its digits is 13122, while the sum is 38.

The square root of 1993691 is about 1411.9812321699. The cubic root of 1993691 is about 125.8594847430.

The spelling of 1993691 in words is "one million, nine hundred ninety-three thousand, six hundred ninety-one".