920981 has 4 divisors (see below), whose sum is σ = 938412. Its totient is φ = 903552.

The previous prime is 920971. The next prime is 920999. The reversal of 920981 is 189029.

920981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 189029 = 421 ⋅449.

It can be written as a sum of positive squares in 2 ways, for example, as 320356 + 600625 = 566^2 + 775^2 .

It is a cyclic number.

It is not a de Polignac number, because 920981 - 2¹⁸ = 658837 is a prime.

It is a super-2 number, since 2×920981² = 1696412004722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 920981.

It is not an unprimeable number, because it can be changed into a prime (920921) 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, 8636 + ... + 8741.

It is an arithmetic number, because the mean of its divisors is an integer number (234603).

2⁹²⁰⁹⁸¹ is an apocalyptic number.

It is an amenable number.

920981 is a deficient number, since it is larger than the sum of its proper divisors (17431).

920981 is a wasteful number, since it uses less digits than its factorization.

920981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17430.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 920981 is about 959.6775500135. The cubic root of 920981 is about 97.2934395319.

The spelling of 920981 in words is "nine hundred twenty thousand, nine hundred eighty-one".