981511 has 4 divisors (see below), whose sum is σ = 990792. Its totient is φ = 972232.

The previous prime is 981493. The next prime is 981517. The reversal of 981511 is 115189.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 115189 = 127 ⋅907.

It is a cyclic number.

It is not a de Polignac number, because 981511 - 2⁹ = 980999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981517) 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, 4480 + ... + 4693.

It is an arithmetic number, because the mean of its divisors is an integer number (247698).

2⁹⁸¹⁵¹¹ is an apocalyptic number.

981511 is a deficient number, since it is larger than the sum of its proper divisors (9281).

981511 is a wasteful number, since it uses less digits than its factorization.

981511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9280.

The product of its digits is 360, while the sum is 25.

The square root of 981511 is about 990.7123699642. The cubic root of 981511 is about 99.3798622412.

The spelling of 981511 in words is "nine hundred eighty-one thousand, five hundred eleven".