120781 has 4 divisors (see below), whose sum is σ = 121500. Its totient is φ = 120064.

The previous prime is 120779. The next prime is 120811. The reversal of 120781 is 187021.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 187021 = 29 ⋅6449.

It can be written as a sum of positive squares in 2 ways, for example, as 36100 + 84681 = 190^2 + 291^2 .

It is a cyclic number.

It is not a de Polignac number, because 120781 - 2¹ = 120779 is a prime.

It is a super-2 number, since 2×120781² = 29176099922, which contains 22 as substring.

It is a Duffinian number.

120781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120721) 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, 45 + ... + 493.

It is an arithmetic number, because the mean of its divisors is an integer number (30375).

2¹²⁰⁷⁸¹ is an apocalyptic number.

It is an amenable number.

120781 is a deficient number, since it is larger than the sum of its proper divisors (719).

120781 is an equidigital number, since it uses as much as digits as its factorization.

120781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 120781 is about 347.5356096863. The cubic root of 120781 is about 49.4310163800.

The spelling of 120781 in words is "one hundred twenty thousand, seven hundred eighty-one".