30688661 has 4 divisors (see below), whose sum is σ = 30930432. Its totient is φ = 30446892.

The previous prime is 30688639. The next prime is 30688703. The reversal of 30688661 is 16688603.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16688603 = 73 ⋅228611.

It is a cyclic number.

It is not a de Polignac number, because 30688661 - 2⁶ = 30688597 is a prime.

It is a super-3 number, since 3×30688661³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30688631) 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, 120695 + ... + 120948.

It is an arithmetic number, because the mean of its divisors is an integer number (7732608).

Almost surely, 2^30688661 is an apocalyptic number.

It is an amenable number.

30688661 is a deficient number, since it is larger than the sum of its proper divisors (241771).

30688661 is a wasteful number, since it uses less digits than its factorization.

30688661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241770.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 30688661 is about 5539.7347409420. The cubic root of 30688661 is about 313.0828750255.

The spelling of 30688661 in words is "thirty million, six hundred eighty-eight thousand, six hundred sixty-one".