981553 has 4 divisors (see below), whose sum is σ = 1013248. Its totient is φ = 949860.

The previous prime is 981527. The next prime is 981569. The reversal of 981553 is 355189.

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: 355189 = 23 ⋅15443.

It is a cyclic number.

It is not a de Polignac number, because 981553 - 2¹⁷ = 850481 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 31663 = 981553 / (9 + 8 + 1 + 5 + 5 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981523) 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, 15801 + ... + 15862.

It is an arithmetic number, because the mean of its divisors is an integer number (253312).

2⁹⁸¹⁵⁵³ is an apocalyptic number.

It is an amenable number.

981553 is a deficient number, since it is larger than the sum of its proper divisors (31695).

981553 is a wasteful number, since it uses less digits than its factorization.

981553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31694.

The product of its digits is 5400, while the sum is 31.

The square root of 981553 is about 990.7335666061. The cubic root of 981553 is about 99.3812797477.

The spelling of 981553 in words is "nine hundred eighty-one thousand, five hundred fifty-three".