30640961 has 4 divisors (see below), whose sum is σ = 32997972. Its totient is φ = 28283952.

The previous prime is 30640957. The next prime is 30640963. The reversal of 30640961 is 16904603.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16904603 = 71 ⋅238093.

It can be written as a sum of positive squares in 2 ways, for example, as 13830961 + 16810000 = 3719^2 + 4100^2 .

It is a cyclic number.

It is not a de Polignac number, because 30640961 - 2² = 30640957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30640963) 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, 1178486 + ... + 1178511.

It is an arithmetic number, because the mean of its divisors is an integer number (8249493).

Almost surely, 2^30640961 is an apocalyptic number.

It is an amenable number.

30640961 is a deficient number, since it is larger than the sum of its proper divisors (2357011).

30640961 is a wasteful number, since it uses less digits than its factorization.

30640961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357010.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 30640961 is about 5535.4278064121. The cubic root of 30640961 is about 312.9205805844.

The spelling of 30640961 in words is "thirty million, six hundred forty thousand, nine hundred sixty-one".