305638 has 4 divisors (see below), whose sum is σ = 458460. Its totient is φ = 152818.

The previous prime is 305633. The next prime is 305639. The reversal of 305638 is 836503.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 836503 = 167 ⋅5009.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (305633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 76408 + ... + 76411.

It is an arithmetic number, because the mean of its divisors is an integer number (114615).

2³⁰⁵⁶³⁸ is an apocalyptic number.

305638 is a deficient number, since it is larger than the sum of its proper divisors (152822).

305638 is a wasteful number, since it uses less digits than its factorization.

305638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152821.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 305638 is about 552.8453671688. The cubic root of 305638 is about 67.3600575769.

The spelling of 305638 in words is "three hundred five thousand, six hundred thirty-eight".