30491661 has 4 divisors (see below), whose sum is σ = 40655552. Its totient is φ = 20327772.

The previous prime is 30491651. The next prime is 30491701. The reversal of 30491661 is 16619403.

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: 16619403 = 3 ⋅5539801.

It is not a de Polignac number, because 30491661 - 2¹⁰ = 30490637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30491651) 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, 5081941 + ... + 5081946.

It is an arithmetic number, because the mean of its divisors is an integer number (10163888).

Almost surely, 2^30491661 is an apocalyptic number.

It is an amenable number.

30491661 is a deficient number, since it is larger than the sum of its proper divisors (10163891).

30491661 is a wasteful number, since it uses less digits than its factorization.

30491661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10163890.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 30491661 is about 5521.9254793958. The cubic root of 30491661 is about 312.4115111588.

The spelling of 30491661 in words is "thirty million, four hundred ninety-one thousand, six hundred sixty-one".