1553993 has 4 divisors (see below), whose sum is σ = 1776000. Its totient is φ = 1331988.

The previous prime is 1553983. The next prime is 1554019. The reversal of 1553993 is 3993551.

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: 3993551 = 311 ⋅12841.

It is not a de Polignac number, because 1553993 - 2⁸ = 1553737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1553983) 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, 110993 + ... + 111006.

It is an arithmetic number, because the mean of its divisors is an integer number (444000).

2^1553993 is an apocalyptic number.

It is an amenable number.

1553993 is a deficient number, since it is larger than the sum of its proper divisors (222007).

1553993 is an equidigital number, since it uses as much as digits as its factorization.

1553993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222006.

The product of its digits is 18225, while the sum is 35.

The square root of 1553993 is about 1246.5925557294. The cubic root of 1553993 is about 115.8287455124.

The spelling of 1553993 in words is "one million, five hundred fifty-three thousand, nine hundred ninety-three".