345981 has 4 divisors (see below), whose sum is σ = 461312. Its totient is φ = 230652.

The previous prime is 345979. The next prime is 345997. The reversal of 345981 is 189543.

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.

It is not a de Polignac number, because 345981 - 2¹ = 345979 is a prime.

It is a super-2 number, since 2×345981² = 239405704722, which contains 22 as substring.

It is a D-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 345981.

It is not an unprimeable number, because it can be changed into a prime (345181) 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, 57661 + ... + 57666.

It is an arithmetic number, because the mean of its divisors is an integer number (115328).

2³⁴⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

345981 is a deficient number, since it is larger than the sum of its proper divisors (115331).

345981 is a wasteful number, since it uses less digits than its factorization.

345981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115330.

The product of its digits is 4320, while the sum is 30.

The square root of 345981 is about 588.2014960879. The cubic root of 345981 is about 70.2022044583.

It can be divided in two parts, 345 and 981, that added together give a triangular number (1326 = T₅₁).

The spelling of 345981 in words is "three hundred forty-five thousand, nine hundred eighty-one".