1993521 has 4 divisors (see below), whose sum is σ = 2658032. Its totient is φ = 1329012.

The previous prime is 1993513. The next prime is 1993529. The reversal of 1993521 is 1253991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1253991 = 3 ⋅417997.

It is an interprime number because it is at equal distance from previous prime (1993513) and next prime (1993529).

It is not a de Polignac number, because 1993521 - 2³ = 1993513 is a prime.

It is a D-number.

It is a Duffinian number.

1993521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1993529) 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, 332251 + ... + 332256.

It is an arithmetic number, because the mean of its divisors is an integer number (664508).

2^1993521 is an apocalyptic number.

It is an amenable number.

1993521 is a deficient number, since it is larger than the sum of its proper divisors (664511).

1993521 is an equidigital number, since it uses as much as digits as its factorization.

1993521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664510.

The product of its digits is 2430, while the sum is 30.

The square root of 1993521 is about 1411.9210317861. The cubic root of 1993521 is about 125.8559073380.

The spelling of 1993521 in words is "one million, nine hundred ninety-three thousand, five hundred twenty-one".