30661 has 2 divisors, whose sum is σ = 30662. Its totient is φ = 30660.

The previous prime is 30649. The next prime is 30671. The reversal of 30661 is 16603.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30625 + 36 = 175^2 + 6^2 .

It is an emirp because it is prime and its reverse (16603) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30661 - 2¹³ = 22469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15330 + 15331.

It is an arithmetic number, because the mean of its divisors is an integer number (15331).

2³⁰⁶⁶¹ is an apocalyptic number.

It is an amenable number.

30661 is a deficient number, since it is larger than the sum of its proper divisors (1).

30661 is an equidigital number, since it uses as much as digits as its factorization.

30661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 30661 is about 175.1028269332. The cubic root of 30661 is about 31.2988781764.

The spelling of 30661 in words is "thirty thousand, six hundred sixty-one".