30945581 has 6 divisors (see below), whose sum is σ = 32043690. Its totient is φ = 29849568.

The previous prime is 30945553. The next prime is 30945583. The reversal of 30945581 is 18554903.

It can be written as a sum of positive squares in 3 ways, for example, as 22005481 + 8940100 = 4691^2 + 2990^2 .

It is not a de Polignac number, because 30945581 - 2⁶ = 30945517 is a prime.

It is a super-2 number, since 2×30945581² = 1915257966855122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30945583) 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, 29441 + ... + 30473.

It is an arithmetic number, because the mean of its divisors is an integer number (5340615).

Almost surely, 2^30945581 is an apocalyptic number.

It is an amenable number.

30945581 is a deficient number, since it is larger than the sum of its proper divisors (1098109).

30945581 is an frugal number, since it uses more digits than its factorization.

30945581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2095 (or 1062 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 30945581 is about 5562.8752457699. The cubic root of 30945581 is about 313.9541395151.

The spelling of 30945581 in words is "thirty million, nine hundred forty-five thousand, five hundred eighty-one".