305649 has 6 divisors (see below), whose sum is σ = 441506. Its totient is φ = 203760.

The previous prime is 305639. The next prime is 305663. The reversal of 305649 is 946503.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 186624 + 119025 = 432^2 + 345^2 .

It is not a de Polignac number, because 305649 - 2⁴ = 305633 is a prime.

It is a super-2 number, since 2×305649² = 186842622402, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (305639) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16972 + ... + 16989.

2³⁰⁵⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

305649 is a deficient number, since it is larger than the sum of its proper divisors (135857).

305649 is a wasteful number, since it uses less digits than its factorization.

305649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33967 (or 33964 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 305649 is about 552.8553156116. The cubic root of 305649 is about 67.3608656699.

The spelling of 305649 in words is "three hundred five thousand, six hundred forty-nine".